Update: we've endorsed hypothes.is on our main notes page. http://cs231n.github.io/
it seemed like the easier way to go, and their video (https://hypothes.is/what-is-it/) is epic. We want to be part of the movement.
Hope that my answer is not too late :). These pages were built with Jekyll https://jekyllrb.com/. It is their default theme. If you follow their tutorial, you will automatically have this theme installed. It's really awesome, very simple to install and has support to render Latex equations (there's a package MathJax, if I recall correctly, which can do that). Wish you good luck with it :)!