🛠 Repo: Add PR compliance action

[JoshuaKGoldberg]

Tooling Suggestion Checklist

• I have tried restarting my IDE and the issue persists.
• I have pulled the latest master branch of the repository.
• I have read and agree to Mocha's Code of Conduct and Contributing Guidelines
• I have searched for related issues and issues with the faq label, but none matched my issue.
• I want to provide a PR to resolve this

Overview

From a meeting with @voxpelli: we'd like to add automation to enforce that PRs adhere to the contributing guidelines. Most notably:

• Have a semantic commit for their title: e.g. feat: add something instead of Adds Something
• Addresses an open issue

Right now, the best action I've found for that is https://github.com/mtfoley/pr-compliance-action. I use it in https://github.com/JoshuaKGoldberg/create-typescript-app and have been pleased with it.

Additional Info

cc @mtfoley 🙂