@dev I'm sure there's a way to do it, since I've seen some people use github issues or discussions as comments systems.

You might want to check out micropub servers as well. I run a microblog that's literally just an html page, and a netlify "serverless" function that receives submissions from a micropub client and converts them to html that gets inserted into the page at a specific target. It works with a github token so I think something similar could be setup with gitea and a small micropub server. You could probably have it automatically commit hugo md files.