I made this after seeing this HN post[0] asking if this was possible.

There are some extensions that can do this, but they also redo lots of the HN UI, which I think is unnecessary.

It just took a few minutes to make; I'm mainly posting this so if someone searches for it they could find it.

Use Tampermonkey or Greasemonkey to install, edit it slightly to add in your domains.

[0] https://news.ycombinator.com/item?id=30468694