📝 Update release notes

docs/en/docs/release-notes.md

@@ -2,6 +2,7 @@
 
 ## Latest changes
 
+* Use OS preference theme for online docs. PR [#1760](https://github.com/tiangolo/fastapi/pull/1760) by [@https://github.com/adriencaccia](https://github.com/adriencaccia).
 * Upgrade Starlette to version `0.13.6` to handle a vulnerability when using static files in Windows. PR [#1759](https://github.com/tiangolo/fastapi/pull/1759) by [@jamesag26](https://github.com/jamesag26).
 * Pin Swagger UI temporarily, waiting for a fix for [swagger-api/swagger-ui#6249](https://github.com/swagger-api/swagger-ui/issues/6249). PR [#1763](https://github.com/tiangolo/fastapi/pull/1763).
 * Update GitHub Actions, use commit from PR for docs preview, not commit from pre-merge. PR [#1761](https://github.com/tiangolo/fastapi/pull/1761).