How to add Changelog verifier to GitHub repo?

How does one go about adding the Changelog verifier (in https://github.com/plone/Products.CMFPlone, for example) to another repo? The GitHub docs are clear as mud...

This is a feature of mr.roboto https://github.com/plone/mr.roboto/blob/master/src/mr.roboto/src/mr/roboto/subscriber.py#L328