Describe what should be investigated or refactored

A workflow should be added to our existing CI to enforce PR titles follow the conventional commits spec

Since we squash all commits in a PR on merge, only the PR title is relevant since that becomes the single commit message when a PR is merged.

The contributing guide should also be updated to reflect this convention.

Links to any relevant code

`https://github.com/defenseunicorns/zarf/tree/main/.github/workflows

Additional context

Should follow this same general pattern:
https://github.com/defenseunicorns/kubernetes-fluent-client/blob/main/.github/workflows/commitlint.yml