Revisit separated footer in contained cards

Our PWA Stats cards have a footer section that's separate from the rest of the card:

Which @AriannaChau accounted for in her designs for contained cards, seen here: #1282

But because those variations represent a significant layout change that would not be used by cloudfour.com proper, I decided to delay on implementing that portion for #1287.

So this issue is a placeholder that represents revisiting that PWA Stats design element at a later date. Possible outcomes may be:

- Implementing the footer as designed in #1282
- Re-thinking the design now that we have a fresh set of patterns to work with
- Punting this design element to PWA Stats entirely

Review the PWA Stats card footer shown in the issue and compare it with the contained-card designs in #1282 and the deferred work in #1287. First establish which outcome is wanted—implement the design, rethink it, or leave it to PWA Stats—then document the selected design and its completion criteria.

Escrito por el modelo de indexación a partir del texto del issue.