[Athen] Listing of web accessibility courses and video tutorials

[Jennifer Sutton]

Greetings, ATHENites and others:


Apologies for cross-posting.

I gathered a lot of what's in here for Mike Gifford, but he built the 
page. If anyone has contributions of courses, tutorials, and/or relevant 
videos, please do suggest them for consideration, via Git, if possible.


Best,
Jennifer


https://github.com/mgifford/a11y-courses