docs(fix[links]): Restore uv reference in developing guide

Author: tony

docs/developing.md

@@ -285,6 +285,7 @@ git push --tags
 ```
 
 [twine]: https://twine.readthedocs.io/
+[uv]: https://github.com/astral-sh/uv
 [entr(1)]: http://eradman.com/entrproject/
 [ruff format]: https://docs.astral.sh/ruff/formatter/
 [ruff]: https://ruff.rs