write-doc

Write new documentation pages for the VitePress docs site at docs/docs/. Ensures correct file structure (index.en.md only), frontmatter, heading hierarchy, media references, VitePress containers, and adherence to writing guidelines. Use when user says "write documentation", "create a doc page", "add documentation for X", "document this feature", "new docs page", or "write a guide for X". Do NOT use for ADR creation…