Hacker News RSS (hnrss): replace broken feed endpoint

When the HNRSS feed for filtered Hacker News stories stopped working in Miniflux, the author discovered the issue stemmed from a broken endpoint. After determining that the problem was not on Miniflux's end, they successfully replaced the broken URL with an alternative instance of HNRSS, which restored access to the desired feed of Hacker News stories with more than 650 points.