Address second round of review feedback

- Simplify next steps: single link per tutorial, add "Create a block" to dashboard tutorial (#23)
- Use shallow clone for blockr.core reference (#24)
- Add "workflow is a Shiny app" and recommend package-based approach in dev docs (#28)

Author: christophsax

docs/dev/create-block.md

@@ -2,7 +2,9 @@
 
 <VideoEmbed id="-PdixmAscQI" title="Creating blocks in blockr" />
 
-Write custom blocks in pure R to extend blockr with your own logic. A block is a specialized Shiny module that returns an **expression** (the R code it generates) and a **state** (its current input values).
+Write custom blocks in pure R to extend blockr with your own logic. A block is a specialized Shiny module that returns an **expression** (the R code it generates) and a **state** (its current input values). A workflow is a Shiny app composed of connected blocks.
+
+Blocks should live in an R package so they can be registered, shared, and tested. The examples below show the package-based approach.
 
 ## Block anatomy
 

learn/01-build-your-first-app.md

@@ -108,5 +108,4 @@ You now have the skills to import, transform, and visualize data in blockr.
 ## Next steps
 
 - [Build a dashboard](02-build-a-dashboard): arrange your pipeline into a shareable layout
-- [Filtering and selecting](/videos/filtering-and-selecting): video deep-dive into data wrangling
 

learn/02-build-a-dashboard.md

@@ -131,5 +131,4 @@ In this case, users can now adjust the filter values and see the effects on the
 
 ## Next steps
 
-- [Export code](/videos/exporting-data): get the R code behind your pipeline
-- [Visualising data](/videos/visualising-data): all chart types and customization options
+- [Create a custom block](03-create-a-block): extend blockr with your own logic

learn/03-create-a-block.md

@@ -10,7 +10,7 @@ Prefer to write blocks by hand? See the [Developer docs](/docs/dev/create-block)
 Clone blockr.core as a reference. Your coding agent will learn the right patterns from it:
 
 ```bash
-git clone https://github.com/BristolMyersSquibb/blockr.core
+git clone --depth 1 https://github.com/BristolMyersSquibb/blockr.core
 ```
 
 ## Create your first block