I have a problem with GitHub Pages, whereby a very simple site (in here) gives a 404 Not Found error. I have tried all eighteen (!) solutions suggested in the different answers to How to fix page 404 on Github Page.
Starting a bounty on a question with 18 existing answers (many of which solved the problem for others experiencing the same issue) seems odd, but re-asking the same question also seems wrong. What is the correct thing to do?