The chat API is experimental (behind `ExperimentAgents`) and not ready
for public documentation yet. This removes swagger annotations from the
chat handlers so they no longer appear in the generated API reference at
https://coder.com/docs/reference/api/chats.
## Changes
- Remove `@swagger` annotations from 5 chat handlers in
`coderd/chats.go`
- Regenerate `coderd/apidoc/swagger.json` and `docs.go`
- Delete `docs/reference/api/chats.md`
- Remove Chats entry from `docs/manifest.json`
Cian Johnston
12bdbc693f