There are umpteen number of blog posts telling you how to host your static site on GitHub Pages for free. They also tell you how to serve such a site from your own domain name.
This is a companion discussion topic for the original entry at https://www.elitmus.com/blog/technology/how-we-host-our-blog-on-github-pages-and-yet-serve-it-from-our-own-sub-url/