Add markdown support

[pyrsmk]

First of all, thanks for this great theme! It mixes the usability of Monokai with 80's style, I love it. Anyway, one big flaw is that there is nearly no markdown support at all.

As it's widely used nowadays, is there any plan to support it?

Cheers!

[AshPowell]

I'll try and find some time to add it at the weekend, thanks for the comments :)

[pyrsmk]

Thanks!