Found a couple of good links that have some decent information on Markdown (though which flavor is up for grabs):

• Markdown code block - supported languages?
• CodeMirror - language mode some good ones here. A couple that I like, in particular:
  • diff
  • shell (what I would suppose is bash)
  • yaml
• MacDown supported …

It seems that if you use a code block (doesn't seem to matter if it's a 'named' block or not (i.e. javascript, bash, etc)), but if you have:

    ```
    ---
    something here
    ```

Then, it will mess your Markdown up pretty royally! You have to do something like the following:

    ```

    --- (note blank …