If it's searching article content as well as just titles/comments, that's already quite interesting and useful. I've long wanted something like that for my browser history, like a "help me find this article I know I read sometime last week about X."
It would be remarkable and interesting to have a super deep search capability that indexes all first-order links on this site.
Show HN: DeepHN - https://news.ycombinator.com/item?id=26791582
Of note, I was able to find that item (which I recalled existed but not by what name) with hn.algolia, but I was not able to find it with the OP search engine, or with the DeepHN search itself. So in my book, Algolia is winning.
But projects like this are super fun and educational to build so props to OP.
Otherwise I snapshot the page to evernote when I think it might be interesting later. Hopefully they don't completely end the free tier.
Otherwise, no thanks.
Of course, local/offline only would be great.