chore: Improve project-wide prettier formatting and ignored files (#5505)

* chore: Improve project-wide prettier formatting and ignored files

* chore: `Run make fmt/prettier`

* Fix gitignore for `.vscode` folder so that ! works

* Add comment in `.prettierrc.yaml` to explain `.editorconfig`

* Remove scripts/apidocgen/markdown-template/README.md

* Use `yq` for processing prettierrc, update lib.sh dependency check

* Add `yq` to Dockerfile and Nix

.prettierrc.yaml

@@ -0,0 +1,16 @@
+# This config file is used in conjunction with `.editorconfig` to specify
+# formatting for prettier-supported files. See `.editorconfig` and
+# `site/.editorconfig`for whitespace formatting options.
+printWidth: 80
+semi: false
+trailingComma: all
+overrides:
+  - files:
+      - README.md
+    options:
+      proseWrap: preserve
+  - files:
+      - "site/**/*.yaml"
+      - "site/**/*.yml"
+    options:
+      proseWrap: always