[tyingq]

That sounded logical, so I searched a bit, and there's several good resources. The two that stood out to me:

This article goes through making a very basic interface, and is easy to follow...ended with 31 lines of js. It isn't production ready, but was a good intro: https://css-tricks.com/building-a-jekyll-site-part-3-of-3/

Then, a more complete implementation. Hasn't been updated for a few years, but has markdown support, up/down voting, flagging, etc: https://commented.github.io/