Wrapping up grid examples

Team,

 

We finished simple data grids, and I believe the layout grid examples are in
pretty good shape for the first release . hoping. Let's please complete a
round of reviews to check.

 

For that we have:

Issue 227: Review Layout Grid Examples

https://github.com/w3c/aria-practices/issues/227

 

As always, as many eyes as possible is best, but I have added Ann, Bryan,
Jemma, and Siri to this one.

 

Matt