Yes! There are some existing projects and posts on the idea of tickets in-the-repo.

Usually the problem is that it's not very friendly for Product Folks and SMEs so I've been working on a local first, git backed project management and documentation tool (Think Jira and Confluence).

So as to not hijack this post, I won't paste a link here (not to mention it's ready for prime time yet) but send me a message if you're interested (it's open source and visible so it's not too hard to find either)