Merge pull request #15 from executablebooks/readme-update

Revise PyPi publishing instructions in README

Author: gaige

README.md

@@ -51,16 +51,10 @@ tox -e py310-hook
 
 ## Publish to PyPi
 
-Either use flit directly:
+Publishing is handled using a trusted action as part of the release process. Authentication is via OIDC
+and should be triggered by creating a release with a tag equal to the version, e.g. `v0.0.1`.
 
-```bash
-pip install flit
-flit publish
-```
-
-or trigger the GitHub Action job, by creating a release with a tag equal to the version, e.g. `v0.0.1`.
-
-Note, this requires generating an API key on PyPi and adding it to the repository `Settings/Secrets`, under the name `PYPI_KEY`.
+Maintainer note: this is configured in PyPI as a trusted repository.
 
 [ci-badge]: https://github.com/gaige/mdformat-footnote/workflows/CI/badge.svg?branch=master
 [ci-link]: https://github.com/gaige/mdformat-footnote/actions?query=workflow%3ACI+branch%3Amaster+event%3Apush