docs: add note about changelog

Author: dhdaines

README.md

@@ -166,6 +166,10 @@ If using the optional `pre-commit`, you'll just need to install the hooks with `
 `pre-commit` package is installed as part of `make install` mentioned above. Finally, if you decided to use `pre-commit`
 you can also uninstall the hooks with `pre-commit uninstall`.
 
+When submitting a pull request, make sure to add an entry to
+[`CHANGELOG.md`](./CHANGELOG.md) (under the development version at the
+top of the file) describing the changes.
+
 In addition to develop in your local OS we also provide a helper to use docker providing a development environment:
 
 ```bash