Adding glyphs to Arabic fonts

Hi Dave et al
I've added a page on the above as you suggested, and also included an (optional) appendix on installing FF on Ubuntu 14.04.  I also added a note to README to say you need ruby-dev installed before gem install jekyll will work. 
Kevin
Generally speaking: can we just put an emphasis on "adding glyphs to a *libre* font" and just mention that SIL OFL and GNU+FE are the kind of license that allow these modifications? 
Better assume that users have a pre-existing clue about licensing and copyright.