Found this thread as the first hit while trying to figure out syntax highlighting, and I found an even easier way to do it that I thought I'd share. Just put the name of the language you want highlighted after the fenced code blocks (reference). No need to generate any css or use yaml.
This is regular text```ruby# This is highlighted codedef foo puts 'foo'end``````python# Here is some in pythondef foo(): print 'foo'```