Doco work

Hi, I started doing some doco work I have been planning to do. As a start I made the sections more clear in the file main.bb, added some text for the most general parts with the hope that this helps some new readers. 
Started FAQ (FAQ for developers ... is this a useful idea or dommed to die? I shamelessly stole a lot from Mike's post.) 
Started to get the distinction more clear: general information, getting started for users, using the Red Matrix more coherently, hub admins and developers. Therefore some new files have been created, some old ones renamed. 
Added back to main page for usability reasons to all appropriate files.