General formatting and legibility changes!

There are a few things that happen with this PR.

1. Clear Sans becomes the new body font.
1. Sponsor logos looked too huge in mobile view; they were wrapped with `sponsor-block` and now have a `max-width` applied to them.
1. Images on the **report** page are wrapped in `figure`s. Images that have the class `.right` applied to them also have margins to the left and bottom so body copy doesn't sit flush with the borders of the image.
1. CSS slightly cleaned up.