chore: clean up (#541)

* chore: move `CONTRIBUTING` to root

This file is not read enough because it's a bit hidden.

* feat(ci): lint using case-police

* style: lint using case-police

* chore: replace GitHub Discussions with Discord

* chore: clean up IDE extensions

* chore: clean up plugins

* chore: clean up tools

Author: innocenzi

.github/workflows/lint.yaml

@@ -8,3 +8,4 @@ jobs:
         with:
           fetch-depth: 0
       - run: npx awesome-lint
+      - run: npx case-police "./README.md"