Add information about packaging maps by ItsMiiOlly, Timothee38 and skipperguy12

So a suggestion was made by Timothee38 about adding information on how to properly package maps. After seeing Apple's comment we decided to work on this.

What we have done is added information about files you should keep/remove, how to prune and how to compile + release.

I originally added the information to the sidebar on the XML page, but after discussion with Plastix we thought it would be better to add it to the toolbar at the top. 

This was my first time coding Ruby HAML. Most of it was just common sense and copying files + editing them, but I'm pretty proud with what me and Tim have done. :P Skipper also helped with some syntax. \o/

Hope you like the work we have done!