refactor: update prettier and doctoc (#5605)

* docs: add toc to CODE OF CONDUCT

* chore: add prettier ignore blocks to docs

* chore: update styles for Dockerfile

* refactor: separate prettier, doctoc

This does a couple things:
- update `.prettierignore`
- split `prettier` and `doctoc` commands. you can still run with `yarn
  fmt`
- delete `fmt.sh` and add `doctoc.sh`

By doing so, we can run tasks in parallel in CI and we should also have
less false positives than before with `yarn fmt` locally.

* refactor: update prettier job, add doctoc

This modifies the prettier job to use actionsx/prettier. It also adds a
job for `doctoc`.

* chore: upgrade to prettier 2.7.1

* chore: pin doctoc to 2.0.0

* fixup!: add .pc to prettierignore

* feat: add --cache to prettier cmd

.prettierignore

@@ -1 +1,5 @@
-lib/vscode
+lib/vscode
+helm-chart
+test/scripts
+test/e2e/extensions/test-extension
+.pc