📝 Update release notes

[skip ci]

Author: github-actions[bot]

release-notes.md

@@ -6,6 +6,10 @@
 
 * ✨ Add implementation of `fastapi-new` CLI, and base for `fastapi new` command. PR [#5](https://github.com/fastapi/fastapi-new/pull/5) by [@savannahostrowski](https://github.com/savannahostrowski).
 
+### Refactors
+
+* 👷 Switch to dynamic versioning with `pdm` build system. PR [#11](https://github.com/fastapi/fastapi-new/pull/11) by [@tiangolo](https://github.com/tiangolo).
+
 ### Internal
 
 * 🔧 Tweak tagline for `pyproject.toml`. PR [#2](https://github.com/fastapi/fastapi-new/pull/2) by [@tiangolo](https://github.com/tiangolo).