Add missing senators from 116th Congress

[pandringa]

This closes #167 by adding images for Rick Scott, Mitt Romney, Josh Hawley, and Mike Braun.

I used a reverse Google Image search to find full-res, uncropped versions of the Rick Scott and Mike Braun photos, and left a comment in their metadata files to note where the full-res image came from. If there's a better way to denote that, let me know and I'd be happy to fix.

• I'm acknowledging that my submission is free of all known copyright in at least the United States. (In general, works of the federal government should satisfy this criteria.)

[hugovk]

Thanks for the PR!

We should document the fields a bit better, we're looking for a short noun and a link to whatever the noun refers to (re: #39 (comment)). Maybe something like this?

[pandringa]

Ah ok, that makes sense - I was a little unclear on what the meta fields were for. Thanks for those corrections!

[hugovk]

Thanks!