Update the README; reformat lines; update generator template

Author: IsaacG

README.md

@@ -7,7 +7,8 @@ Exercism exercises in Go.
 
 ## Issues/Feedback
 
-⚠️ Please be aware that this repository currently does not accept community contributions. This [blog post](https://exercism.org/blog/freeing-our-maintainers) explains the details.
+⚠️ Please be aware that this repository currently does not accept community contributions.
+This [blog post](https://exercism.org/blog/freeing-our-maintainers) explains the details.
 
 If you have any feedback or experience problems, you can bring them up in the [Go section of the Exercism forum](https://forum.exercism.org/c/programming/go/19).
 
@@ -20,16 +21,17 @@ You should have a [recent version of Go](http://golang.org/doc/install) installe
 You will need a github account and you will need to fork exercism/go to your account.
 See [GitHub Help](https://help.github.com/articles/fork-a-repo/) if you are unfamiliar with the process.
 Clone your fork with the command: `git clone https://github.com/<you>/go`.
-Test your clone by cding to the go directory and typing `bin/fetch-golangci-lint` and then
-`bin/run-tests`. You should see tests pass for all exercises.
+Test your clone by cding to the go directory and typing `bin/fetch-golangci-lint` and then `bin/run-tests`.
+You should see tests pass for all exercises.
 
 Note that unlike most other Go code, it is not necessary to clone this to your GOPATH.
 This is because this repo only imports from the standard library and isn't expected to be imported by other packages.
 
 Your Go code should be formatted using the [gofmt](https://golang.org/cmd/gofmt/) tool.
 
-There is a [misspelling tool](https://github.com/client9/misspell). You can install and occasionally run it to
-find low hanging typo problems. [#570](https://github.com/exercism/go/pull/570) It's not added into CI since it could give false positives.
+There is a [misspelling tool](https://github.com/client9/misspell).
+You can install and occasionally run it to find low hanging typo problems.
+[#570](https://github.com/exercism/go/pull/570) It's not added into CI since it could give false positives.
 
 ## Contributing Guide
 
@@ -39,14 +41,12 @@ In particular, please read the [Pull Request Guidelines](https://github.com/exer
 
 ## Exercism Go style
 
-Let's walk through an example, non-existent, exercise, which we'll call
-`fizzbuzz` to see what could be included in its implementation.
+Let's walk through an example, non-existent, exercise, which we'll call `fizzbuzz` to see what could be included in its implementation.
 
 ### Exercise configuration
 
-An exercise is configured
-via an entry in the exercises array in [config.json file](/config.json). If `fizzbuzz` is an optional
-exercise, it would have an entry below the core exercises that might look like:
+An exercise is configured via an entry in the exercises array in [config.json file](/config.json).
+If `fizzbuzz` is an optional exercise, it would have an entry below the core exercises that might look like:
 
 ```json
 {
@@ -59,8 +59,7 @@ exercise, it would have an entry below the core exercises that might look like:
 }
 ```
 
-See [Exercism Docs: config.json](https://exercism.org/docs/building/tracks/config-json)
-for more info.
+See [Exercism Docs: config.json](https://exercism.org/docs/building/tracks/config-json) for more info.
 
 ### Exercise files: Overview
 
@@ -102,8 +101,11 @@ Let's briefly describe each file:
 
 - **fizzbuzz_test.go** - The main test file for the exercise.
 
-- **.meta/** - Contains files not to be included when a user fetches an
-  exercise: See also [ignored files](#ignored-files).
+- **go.mod** - The Go module file.
+  This should be automatically generated by the generator code.
+
+- **.meta/** - Contains files not to be included when a user fetches an exercise.
+  See also [ignored files](#ignored-files).
 
 - **.meta/description.md** - Use to generate a [track specific description](https://github.com/exercism/docs/blob/master/language-tracks/exercises/anatomy/readmes.md) of the exercise in the exercise's README.
 
@@ -139,14 +141,12 @@ Examples can be plain, simple, concise, even naïve, as long as they are correct
 
 Stub files, such as _leap.go_, are a starting point for solutions.
 Not all exercises need to have a stub file, only exercises early in the syllabus.
-By convention, the stub file for an exercise with slug `exercise-slug`
-must be named `exercise_slug.go`. This is because CI needs to delete stub files
-to avoid conflicting definitions.
+By convention, the stub file for an exercise with slug `exercise-slug` must be named `exercise_slug.go`.
+This is because CI needs to delete stub files to avoid conflicting definitions.
 
 ### Tests
 
-The test file is fetched for the solver and deserves
-attention for consistency and appearance.
+The test file is fetched for the solver and deserves attention for consistency and appearance.
 
 The `leap` exercise makes use of data-driven tests.
 Test cases are defined as data, then a test function iterates over the data.
@@ -156,60 +156,52 @@ The _cases_test.go_ file is generated by information found in [problem-specifica
 To add additional test cases (e.g. test cases that only make sense for Go) add the test cases to `<exercise>_test.go`.
 An example of using additional test cases can be found in the exercise [two-bucket](exercises/practice/two-bucket/two_bucket_test.go).
 
-Identifiers within the test function appear in actual-expected order as described
-at [Useful Test Failures](https://github.com/golang/go/wiki/CodeReviewComments#useful-test-failures).
-Here the identifier `observed` is used instead of actual. That's fine. More
-common are words `got` and `want`. They are clear and short. Note [Useful Test
-Failures](https://github.com/golang/go/wiki/CodeReviewComments#useful-test-failures)
-is part of [Code Review Comments](https://github.com/golang/go/wiki/CodeReviewComments).
+Identifiers within the test function appear in actual-expected order as described at [Useful Test Failures](https://github.com/golang/go/wiki/CodeReviewComments#useful-test-failures).
+Here the identifier `observed` is used instead of actual.
+That's fine.
+More common are words `got` and `want`.
+They are clear and short.
+Note [Useful Test Failures](https://github.com/golang/go/wiki/CodeReviewComments#useful-test-failures) is part of [Code Review Comments](https://github.com/golang/go/wiki/CodeReviewComments).
 Really we like most of the advice on that page.
 
 In Go we generally have all tests enabled and do not ask the solver to edit the test program, to enable progressive tests for example.
 `t.Fatalf()`, as seen in the _leap_test.go_ file, will stop tests at the first failure encountered, so the solver is not faced with too many failures at once.
 
 ### Testable examples
 
-Some exercises can contain [Example tests](https://blog.golang.org/examples)
-that document the exercise API. These examples are run alongside the standard
-exercise tests and will verify that the exercise API is working as expected.
-They are not required by all exercises and are not intended to replace the
-data-driven tests. They are most useful for providing examples of how an
-exercise's API is used. Have a look at the example tests in the [clock exercise](https://github.com/exercism/go/blob/master/exercises/clock/example_clock_test.go)
-to see them in action.
+Some exercises can contain [Example tests](https://blog.golang.org/examples) that document the exercise API.
+These examples are run alongside the standard exercise tests and will verify that the exercise API is working as expected.
+They are not required by all exercises and are not intended to replace the data-driven tests.
+They are most useful for providing examples of how an exercise's API is used.
+Have a look at the example tests in the [clock exercise](https://github.com/exercism/go/blob/master/exercises/clock/example_clock_test.go) to see them in action.
 
 ### Errors
 
-We like errors in Go. It's not idiomatic Go to ignore invalid data or have undefined
-behavior. Sometimes our Go tests require an error return where other language
-tracks don't.
+We like errors in Go.
+It's not idiomatic Go to ignore invalid data or have undefined behavior.
+Sometimes our Go tests require an error return where other language tracks don't.
 
 ### Benchmarks
 
-In most test files there will also be benchmark tests, as can be seen at the end
-of the _leap_test.go_ file. In Go, benchmarking is a first-class citizen of the
-testing package. We throw in benchmarks because they're interesting, and because
-it is idiomatic in Go to think about performance. There is no critical use for
-these though. Usually they will just bench the combined time to run over all
-the test data rather than attempt precise timings on single function calls. They
-are useful if they let the solver try a change and see a performance effect.
+In most test files there will also be benchmark tests, as can be seen at the end of the _leap_test.go_ file.
+In Go, benchmarking is a first-class citizen of the testing package.
+We throw in benchmarks because they're interesting, and because it is idiomatic in Go to think about performance.
+There is no critical use for these though.
+Usually they will just bench the combined time to run over all the test data rather than attempt precise timings on single function calls.
+They are useful if they let the solver try a change and see a performance effect.
 
 ## Synchronizing exercises with problem specifications
 
-Some problems that are implemented in multiple tracks use the same inputs and
-outputs to define the test suites.
-Where the [problem-specifications](https://github.com/exercism/problem-specifications)
-repository contains a _canonical-data.json_ file with these inputs and outputs,
-we can generate the test cases programmatically.
+Some problems that are implemented in multiple tracks use the same inputs and outputs to define the test suites.
+Where the [problem-specifications](https://github.com/exercism/problem-specifications) repository contains a _canonical-data.json_ file with these inputs and outputs, we can generate the test cases programmatically.
 The problem-specifications repo also defines the instructions for the exercises, which are also shared across tracks and must also be synchronized.
 
 ### Test structure
 
-See the _gen.go_ file in the `leap` exercise for an example of how this
-can be done.
+See the _gen.go_ file in the `leap` exercise for an example of how this can be done.
 
-Test case generators are named _gen.go_ and are kept in a special _.meta_
-directory within each exercise that makes use of a test cases generator. This
-_.meta_ directory will be ignored when a user fetches an exercise.
+Test case generators are named _gen.go_ and are kept in a special _.meta_ directory within each exercise that makes use of a test cases generator.
+This _.meta_ directory will be ignored when a user fetches an exercise.
 
 Whenever the shared JSON data changes, the test cases will need to be regenerated.
 The generator will first look for a local copy of the **problem-specifications** repository.
@@ -229,7 +221,7 @@ $ tree -L 1 .
 
 #### Adding a test generator to an exercise
 
-For some exercises, a test generator is used to generate the `cases_test.go` file with the test cases based on information from [problem-specifications](https://github.com/exercism/problem-specifications).
+For most exercises, a test generator is used to generate the `cases_test.go` file with the test cases based on information from [problem-specifications](https://github.com/exercism/problem-specifications).
 To add a new exercise generator to an exercise the following steps are needed:
 1. Create the file `gen.go` in the directory `.meta` of the exercise
 2. Add the following template to `gen.go`:
@@ -258,18 +250,23 @@ func main() {
 }
 ```
 3. Insert the name of the exercise to the call of `gen.Gen`
-4. Add all values for the field `property` in `canonical-data.json` to the map `j`. `canonical-data.json` can be found at [problem-specifications/exercises/\<exercise-name\>](https://github.com/exercism/problem-specifications)
+4. Add all values for the field `property` in `canonical-data.json` to the map `j`.
+   `canonical-data.json` can be found at [problem-specifications/exercises/\<exercise-name\>](https://github.com/exercism/problem-specifications)
 5. Create the needed structs for storing the test cases from `canonical-data.json` (you can for example use [JSON-to-Go](https://mholt.github.io/json-to-go/) to convert the JSON to a struct)
 
-**NOTE:** In some cases, the struct of the data in the `input`/`expected` fields is not the same for all test cases of one property. In those situations, an `interface{}` has to be used to represent the values for these fields.  These `interface{}` values then need to be handled by the test generator. A common way to handle these cases is to create methods on the test case structs that perform type assertions on the `interface{}` values and return something more meaningful. These methods can then be referenced/called in the `tmpl` template variable. Examples of this can be found in the exercises [forth](https://github.com/exercism/go/blob/main/exercises/practice/forth/.meta/gen.go) or [bowling](https://github.com/exercism/go/blob/main/exercises/practice/bowling/.meta/gen.go).
+**NOTE:** In some cases, the struct of the data in the `input`/`expected` fields is not the same for all test cases of one property.
+In those situations, an `interface{}` has to be used to represent the values for these fields.
+These `interface{}` values then need to be handled by the test generator.
+A common way to handle these cases is to create methods on the test case structs that perform type assertions on the `interface{}` values and return something more meaningful.
+These methods can then be referenced/called in the `tmpl` template variable.
+Examples of this can be found in the exercises [forth](https://github.com/exercism/go/blob/main/exercises/practice/forth/.meta/gen.go) or [bowling](https://github.com/exercism/go/blob/main/exercises/practice/bowling/.meta/gen.go).
 
-6. Add the variable `tmpl` to `gen.go`. This template will be used to create the `cases_test.go` file.
+6. Add the variable `tmpl` to `gen.go`.
+   This template will be used to create the `cases_test.go` file.
 
 Example:
 ```go
-var tmpl = `package <package of exercise>
-
-{{.Header}}
+var tmpl = `{{.Header}}
 
 var testCases = []struct {
 	description    string
@@ -321,7 +318,8 @@ Try providing a GitHub access token with the flag `-github_token="<Token>"`.
 Using the token will result in a higher rate limit.
 The token does not need any specific scopes as it is only used to fetch infos about commits.
 
-You should see that some/all of the above files have changed. Commit the changes.
+You should see that some/all of the above files have changed.
+Commit the changes.
 
 ### Synchronizing all exercises with generators
 
@@ -375,15 +373,17 @@ If there's a problem, it comes up red:
 <img src="img/mars3.png">
 
 This means you've still got work to do.
-Click on "details" to go to the CI build details. Look over the build log for clues.
+Click on "details" to go to the CI build details.
+Look over the build log for clues.
 Usually error messages will be helpful and you can correct the problem.
 
 ## Direction
 
 Directions are unlimited.
 This code is fresh and evolving.
 Explore the existing code and you will see some new directions being tried.
-Your fresh ideas and contributions are welcome. :sparkles:
+Your fresh ideas and contributions are welcome.
+:sparkles:
 
 ### Go icon