Change favicon to ORNL favicon
A "favicon" is the icon that appears in your browser's tab for a website:
We should change this from the LLNL icon to the ORNL icon, which can be found here: https://www.ornl.gov/themes/custom/ornl/images/favicons/favicon-16x16.png
We would like to host this icon locally, though, not from the ORNL website. (We don't have a dedicated CDN, so the location of the favicon is subject to change.)