refactor: Replace linting configurations

The previous package was outdated, preventing us from updating TS.
This one also lints YAML and JSON,
and applies many more rules to the test files,
explaining all the changes in this PR.

.github/workflows/main.yml

@@ -2,7 +2,7 @@ name: CI
 on:
   push:
     branches:
-      - 'main'
+      - main
       - 'versions/*'
     tags:
       - 'v*'
@@ -14,11 +14,11 @@ concurrency:
 
 jobs:
   npm-test:
-  # Run the tests in every case
+    # Run the tests in every case
     uses: ./.github/workflows/npm-test.yml
 
   cth-test:
-  # Run the Conformance Test Harness on PRs targeting main or versions/
+    # Run the Conformance Test Harness on PRs targeting main or versions/
     if: github.event_name == 'pull_request' && ( github.base_ref == 'main' || startsWith( github.base_ref, 'versions/' ) )
     uses: ./.github/workflows/cth-test.yml
     with:
@@ -26,7 +26,7 @@ jobs:
       version: 1.1.14 # The latest version that CSS is confirmed to pass
 
   docker:
-  # Build docker containers on version tag, push to main and push to versions/
+    # Build docker containers on version tag, push to main and push to versions/
     needs: npm-test
     if: startsWith(github.ref, 'refs/tags/v') || (github.ref == 'refs/heads/main') || startsWith(github.ref, 'refs/heads/versions/')
     uses: ./.github/workflows/docker.yml
@@ -35,6 +35,6 @@ jobs:
       DOCKERHUB_TOKEN: ${{ secrets.DOCKERHUB_TOKEN }}
 
   mkdocs-release:
-  # Release documentation on version tag, but ignore pre-releases
+    # Release documentation on version tag, but ignore pre-releases
     if: startsWith(github.ref, 'refs/tags/v') && !contains(github.ref, '-')
     uses: ./.github/workflows/mkdocs.yml