## What changes were proposed in this pull request?

Coincidentally, I discovered that a couple images were unused in `docs/`, and then searched and found more, and then realized some PNGs were pretty big and could be crushed, and before I knew it, had done the same for the ASF site (not committed yet).

No functional change at all, just less superfluous image data.

## How was this patch tested?

`jekyll serve`

Author: Sean Owen <sowen@cloudera.com>

Closes #14029 from srowen/RemoveCompressImages.