Turns out they have their own system for moving from math-heavy markdown to HTML or LaTeX: bookish (“Bookish – math-infested markdown to HTML and latex”)
I know everyone wants an HTML version of the manual. Maybe this tool could help?
I’m pretty happy with bookdown—the formats are way better than all the knitr formats other than the Tufte format. I really like the latter, which I used for my latest case study: