Add recommended vscode extensions! 💻 (#34)

.vscode/extensions.json

@@ -0,0 +1,10 @@
+{
+  // See http://go.microsoft.com/fwlink/?LinkId=827846
+  // for the documentation about the extensions.json format
+  "recommendations": [
+    "DigitalAssetHoldingsLLC.ghcide",
+    "hoovercj.haskell-linter",
+    "vigoo.stylish-haskell",
+    "EditorConfig.EditorConfig"
+  ]
+}

DEVELOPMENT.md

@@ -3,6 +3,7 @@
 Before continuing, make sure you've read:
 
 - [Alejandro's post on setting up a Haskell development environment](https://www.47deg.com/blog/setting-up-haskell/).
+- [Kowainik's Haskell Style Guide](https://kowainik.github.io/posts/2019-02-06-style-guide).
 
 ## VSCode extensions
 
@@ -23,4 +24,14 @@ $ ...
 $ cd stylish-haskell && stack install
 ```
 
+We don't provide any git hook or tool that enforces our style. However, before you propose any PR please make sure to run `stylish-haskell` yourself, and to follow our style guide mentioned above to the extent possible. 😊
+
+If you wan't to automate this for your VSCode, add the following to your `.vscode/settings.json`:
+
+```json
+{
+  "editor.formatOnSave": true
+}
+```
+
 Happy hacking! 👏🏼