WAI glossary start

I have an action in WAI-CC to get a start on a WAI-wide Glossary. I've 
compiled glossaries from all the WAI documents I knew about and sorted 
them to allow comparison of terms, with indication of each term's 
source. The result is, for now, at:

https://docs.google.com/document/d/1MDW5ja90OVuCSbirmOLfKcnHdgEKOUvqFy5icPwGsdY/edit?usp=sharing

There is additional information and suggested next steps at the top of 
the document. I think this is ready for review at an upcoming WAI-CC 
meeting.

As far as a tool in which to host the glossary, I don't yet have a 
proposal. The respec data-export feature and the webref database looked 
like a central W3C glossary emerging, but the documentation is clear 
it's only for "browser specs". But I'm sure we'll be able to sort that 
side without too much difficulty.

Michael