In addition to the prior art the author links in the README, there's also the suckless.org project ssg[0]. For something a little more graphically oriented, there's Tom MacWright's big[1] and the in-browser slide editor biggie[2], which both use Markdown.
1: https://github.com/jroimartin/ssg
2: http://www.macwright.org/big/
3: http://www.macwright.org/biggie/