Add support for right-to-left languages

[mohsend]

There isn't a decent Markdown editor available for RTL languages (Persian, Arabic, Hebrew). Given the web based nature of this editor adding RTL support should be pretty straight-forward. Maybe a button or a keyboard shortcut can toggle between RTL/LTR?

[jbt]

I have to admit I have absolutely no knowledge of how RTL works on the web so I'm probably not going to be able to do this myself. But if you or anyone else can figure out exactly what'd be necessary to make it happen then it'd definitely be great to add!

[mohsend]

I have some experience with making webpages RTL. My first attempts failed. but I'm sure after reviewing the code and trying again it is possible. I'll fork and set to work.