📝 Update release notes

[skip ci]

Author: github-actions[bot]

docs/release-notes.md

@@ -4,6 +4,7 @@
 
 ### Features
 
+* ✨ Support `typing.Literal` to define a set of predefined choices. PR [#429](https://github.com/fastapi/typer/pull/429) by [@blackary](https://github.com/blackary).
 * ✨ Allow setting an environment variable to `None` in `CliRunner.invoke`. PR [#1303](https://github.com/fastapi/typer/pull/1303) by [@arjenzorgdoc](https://github.com/arjenzorgdoc).
 * ✅ Use Ruff rules to ensure safe lazy-loading of `rich`. PR [#1297](https://github.com/fastapi/typer/pull/1297) by [@nathanjmcdougall](https://github.com/nathanjmcdougall).