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

docs/CODE_OF_CONDUCT.md

@@ -1,5 +1,18 @@
+<!-- prettier-ignore-start -->
 <!-- START doctoc generated TOC please keep comment here to allow auto update -->
 <!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
+# Contributor Covenant Code of Conduct
+
+- [Contributor Covenant Code of Conduct](#contributor-covenant-code-of-conduct)
+  - [Our Pledge](#our-pledge)
+  - [Our Standards](#our-standards)
+  - [Our Responsibilities](#our-responsibilities)
+  - [Scope](#scope)
+  - [Enforcement](#enforcement)
+  - [Attribution](#attribution)
+
+<!-- END doctoc generated TOC please keep comment here to allow auto update -->
+<!-- prettier-ignore-end -->
 
 # Contributor Covenant Code of Conduct