Add suggestions to CONTRIBUTING.md

Author: Gaurav0

CONTRIBUTING.md

@@ -66,3 +66,12 @@ Make use of the many generators for code, try `ember help generate` for more det
   * Ember logo
 * Otherwise, try to keep the overall theme as close to other Ember websites as possible.
 
+### Suggestions
+
+* Try to only fix one issue and/or upgrade one version. You are more likely to be able to succeed.
+* Upgrading the ember-cli version is extremely difficult, because we are using private apis. Try to upgrade in small pieces. Consider forking ember-cli during the upgrade process to upgrade its dependencies one by one. Don't forget to revert to a standard ember-cli version when done.
+* Add tests with your PR.
+* Upgrading ember-cli is usually not necessary to upgrade Ember or Ember Data.
+* New Ember versions will not work without upgrades to the backend.
+* The backend does not have tests. Until it does, please test by actually compiling addons with Docker and an AWS account before submitting PRs.
+* If you are going to use a local backend, make changes to environment.js using [`git update-index skip-worktree [<file>...]`](https://medium.com/@igloude/git-skip-worktree-and-how-i-used-to-hate-config-files-e84a44a8c859) so that changes to your environment.js are not accidentally committed.

README.md

@@ -6,6 +6,7 @@ An ember cli like web based javascript sharing tool. http://ember-twiddle.com
 
 * Ember Twiddle uses [Github Gists](https://gist.github.com) as persistence layer. Once you hit `Save` on a newly created Twiddle, it will create a public Gist under your Github account.
 * If you'd like to help out, check out [CONTRIBUTING.md](CONTRIBUTING.md) We are looking for help maintaining the project. If you have contributed and would like to be made a maintainer, please make a request on the Slack channel or via email.
+* Ember Twiddle uses a backend for compiling addons. It is currently located at https://github.com/joostdevries/twiddle-backend
 
 ### Browser support