* Document avatar removal API endpoint
* Document notification settings API endpoints
* Document access token list and delete API endpoints
* Document join code API endpoints
* Fix access token delete URL parameter name in docs
* Split docs/API.md into per-resource sections under docs/api/
* Move API endpoints index above authentication in docs/api/README.md
* Fix trailing comma in boards.md JSON example
* Fix trailing comma in cards.md, add Response label to identity.md, add Rich Text to endpoint index
Rob Zolkos