Markdown Syntax Highlighting! :clap:

After 2 months of work and ~6,000 lines of code, this is finally finished!
![markdown-code-demo](https://f.cloud.github.com/assets/313894/1718921/24caacb0-61e5-11e3-9c5b-0f589b6c3ffb.png)
![markdown-errors-intellisense](https://f.cloud.github.com/assets/313894/1718922/24dca924-61e5-11e3-954b-1cde532f49bb.png)

For more info, see http://blog.slaks.net/2013-12-10/syntax-highlighted-markdown-code-blocks-web-essentials/