📝 Update release notes

Author: tiangolo

docs/en/docs/release-notes.md

@@ -2,6 +2,7 @@
 
 ## Latest changes
 
+* Deep merge OpenAPI responses to preserve all the additional metadata. PR [#1577](https://github.com/tiangolo/fastapi/pull/1577).
 * Mention in docs that only main app events are run (not sub-apps). PR [#1554](https://github.com/tiangolo/fastapi/pull/1554) by [@amacfie](https://github.com/amacfie).
 * Fix body validation error response, do not include body variable when it is not embedded. PR [#1553](https://github.com/tiangolo/fastapi/pull/1553) by [@amacfie](https://github.com/amacfie).
 * Fix testing OAuth2 security scopes when using dependency overrides. PR [#1549](https://github.com/tiangolo/fastapi/pull/1549) by [@amacfie](https://github.com/amacfie).