Did you notice you can filter HN posts by a domain of their link?
Try: https://news.ycombinator.com/from?site=github.com
I couldn't find a link or description of such feature anywhere on HN. It appears on the top menu just when you visit that page. I got there just by a chance from Google search results.
Just replace the "site" parameter in the URL with whatever domain you want and you'll get a list of HN posts containing links to that domain.