We use GitHub Pages exclusively for our web design assignments. The students host all of their weekly assignments, final projects & their portfolio websites on GitHub Pages.
I generally set up each repo with a
gh-pages branch so when the students fork it it’s already live.
My whole curriculum used to be on GitHub Pages too, but I unfortunately had to move it off after the Jekyll update that added automatic code syntax highlighting and it completely ruined my tutorials. All of the curriculum is still committed to GitHub repos, just not hosted any more.