[alreq] Create a section Arabic Script Overview

r12a has just created a new issue for https://github.com/w3c/alreq:

== Create a section Arabic Script Overview ==
While working on the Tibetan layout requirements doc at 
http://w3c.github.io/tlreq/ it seemed useful to separate out the 
information that simply described how the script worked into a 
separate section, Tibetan script overview.  The actual layout 
requirements start in the following section, Typography for Tibetan 
Characters.

i suspect that a similar Arabic Script Overview section could be 
useful to gather together descriptive text for alreq.

Please view or discuss this issue at 
https://github.com/w3c/alreq/issues/12 using your GitHub account