add: implement markdown link checking #78

	# This workflow ensures markdown files follow our style guide
	# Logic:
	# 1. Runs on every push and PR
	# 2. Uses markdownlint-cli2 (same as local)
	# 3. Attempts to auto-fix issues and commits them
	# 4. If fixes aren't possible, fails the check

	name: Markdown Lint

	on:
	push:
	paths:
	- '*/.md'
	pull_request:
	paths:
	- '*/.md'

	jobs:
	markdownlint:
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v4
	- uses: actions/setup-node@v4
	with:
	node-version: '20'
	cache: 'npm'
	- run: npm ci
	- name: Fix markdown
	run: npm run fix:md
	- name: Commit fixes
	uses: stefanzweifel/git-auto-commit-action@v5
	with:
	commit_message: "chore: auto-fix markdown formatting"
	file_pattern: "*.md"
	- name: Check remaining issues
	uses: DavidAnson/markdownlint-cli2-action@v13
	with:
	globs: '*/.md'

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