Improve UI adding some features

[gnacho]

I have some ideas I just dropped in this link: https://github.com/gnacho/Gnome-MD

Take a look and feel free to use it in any way you want :)

[Mandarancio]

Thank you @gnacho! We really like your design, and we already discussed it. We would like to add some of the design elements of your mockups in our editor, I'm now working on a better source view focused on markdown only for the moment!