markdown-linting

Markdown linting for this workspace: MD029 list numbering, MD040 code block language tags, MD051 anchor links, and the closing-fence mistake that breaks HTML generation. Use when: writing or editing any .md file, running markdownlint-cli2, fixing MD029/MD040/MD051 errors, generating HTML or PDF from markdown. Do NOT use for: the general documentation standard (use the documentation skill) — this is the linter-specific subset.