To research doc tables add internal and align-top

[shawna-slh]

Ref: https://w3c.github.io/coga/user-research/

With large text, it is impossible to understand the large table under https://w3c.github.io/coga/user-research/#summary-of-user-groups-and-cognitive-function

Adding (internal and external) borders and top aligning the content would help significantly.

[lseeman]

Thanks Shawn. we will look at it for the next version