A simple GitHub action that makes sure all commit messages are following the [Conventional Commits](https://www.conventionalcommits.org/en/v1.0.0-beta.2/) specification.
Note that, typically, you would make this check on a pre-commit hook (for example, using something like [Commitlint](https://commitlint.js.org/)), but those can easily be skipped, hence this GitHub action.