[docs][website] remove border around blockquote (#10238)
[docs][website] remove border around blockquote (#10238)

When I unified the CSS for the docs and the website, every block quote in
the docs (including all bulleted lists) received a border. `style.css` originally
came from the main Hail website (https://hail.is, https://hail.is/references.html, etc.).
I cannot find any place where we needed a border around a blockquote, so I
have removed the blockquote border rules and consolidated the pre rules into
one block.
hail-is/hail,hail-is/hail,hail-is/hail,hail-is/hail,hail-is/hail,hail-is/hail,hail-is/hail,hail-is/hail