New docs site with Markdown for agents
The documentation now lives at /docs, organized as Get started, Guides, Concepts, Reference and For
agents, with full-text search. Every page is also served as Markdown at /docs/source/<path>.md, and the whole site
as /docs/llms.txt and /llms-full.txt.
Coding agents can connect over MCP from /connect, or read the setup as /connect.md.
Links to the previous docs redirect to their new pages.