Teaching Other Markup Languages
Next year I'm planning on having some of my second and third year students build an API that can then be used by students in our mobile development classes, and possibly web development classes.

Hadn't thought of this before reading your post, but I think I may have part of the requirements be that they write documentation for the API so that the other classes can use it without having direct interaction with the authors. Since git, and specifically GitHub, is part of the task it makes sense that the documentation should be written in markdown. Seems like a good excuse to go over it in class.

A couple years ago I had a student that started teaching themselves Latex as part of an independent project. His goal was to create a calculus equation solver. He did fairly well learning Latex, but I'm not sure how I would go about bridging that in to a full class project.