Add markdown support as Text format

Markdown is a lightweight markup language with plain text formatting syntax designed so that it can be converted to HTML and many other formats using a tool by the same name. Markdown is often used to format readme files, for writing messages in online discussion forums, and to create rich text using a plain text editor.




+4. Although I'm voting to make it the only acceptable formatting language used. Not just to add it.

Why would you want to limit it as the only formatting language used?  That would make it more difficult for people to add marked-up posts and could be a barrier to entry for people.  Providing different options makes it more accessible for people to  participate.