tzk/RELEASING.md

1. Run 'tzk build emptify' in the parent directory; this will update the single-file (for GitHub Pages) and edition (for the PyPi package) versions. Ensure that the emptified build looks how you want it.
2. Update version numbers: setup.py, cli_docs/conf.py, tzk/util.py.
3. Push changes to GitHub. Check that RTD and GitHub Pages update as desired (https://tzk.readthedocs.io/en/latest/, https://sobjornstad.github.io/tzk/).
4. Run publish.sh, which will upload the latest package version to PyPi.