Minor maintenance release:
- Releases are now performed with release-plz.
- Add a short AI-contributions policy.
Other
- Add release-plz config.
- Minor dependency bump.
- Ignore emacs rust-analyser settings.
- Change default branch from 'main' to 'master'
- Include AI Contribution Policy in README
- Bump dependencies.
- Add release-plz workflow.
- Fix root test.
- Update github tests with rust helper actions.
- Add emacs restore files to .gitignore.
- Minor clippy improvement.
- Remove circleci from badges.
- Remove circleci builds as they're not kept up to date currently.