show the rss icon before latest news header
Revert "show the rss icon before latest news header"

This reverts commit 62429283e782c9c9255b9f89d42a6a27d80b970d.
switch to raw html and make the rss icon clickable
Revert f10efdd863f578399806a913d5023407fd54d183 and e88f8472c53e46d6f1c47b6d4dc3eb0412d9d0f4.

The outline is useful for accessibility.
index.rst: add an abbr for MPC-HC