ci: Add conventional commits workflow

[ewuerger]

No description provided.

[github-actions]

The pull request does not conform to the conventional commit specification. Please ensure that your commit messages follow the spec: https://www.conventionalcommits.org/.
We also strongly recommend that you set up your development environment with pre-commit.

This is the commit validation log:

⧗   input: ci: Add conventional commits workflow
✖   Please add rules to your `commitlint.config.js`
    - Getting started guide: https://commitlint.js.org/guides/getting-started
    - Example config: https://github.com/conventional-changelog/commitlint/blob/master/%40commitlint/config-conventional/src/index.ts [empty-rules]

✖   found 1 problems, 0 warnings
ⓘ   Get help: https://github.com/conventional-changelog/commitlint/#what-is-commitlint

Here are some examples of valid commit messages:

feat(model): Add realized_states to State and Mode
fix(aird): Prevent creating circles with r=0
docs(readme): Update project description