plasticboy/vim-markdown — pull request #28 by beala (2012-03-14 23:02:45+00:00)
Title: Added a rule that covers "Github Flavored Markdown" (GFM) code blocks

GFM takes three back ticks to start a code block. It can be followed with a word specifying the language. It then ends with three back ticks.
http://github.github.com/github-flavored-markdown/