Remove stale duplicate API-Reference.md (superseded by API-Overview.md)
Add Getting Started, API Overview, and Advanced Usage pages Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01Pp8esHnVsdHzNSyAxVY7Fj
Add wiki: Home, Getting Started, API Reference
Initial Home page