Documentation now lives in the docs site

The README has been trimmed to a short repository overview, license note, and docs link. Detailed sections about projects and domains, Model Context Protocol, forage, drops, subscriptions, and Slack have been removed from README.md and now live only on the docs site. Contributors also get updated guidance in AGENTS.md to point feature changes to the docs instead of the README. Users who land on the repository are now directed to the docs site for product and self-hosting details.