[RFE] Make link to GitHub more visible

[kastl-ars]

Current situation

There is a small icon way on the bottom of the page, that links to the Flatcar github organization. Easy to overlook and hard to find, as it does not contain the string "github", so searching the page does not find it.

Ideal future situation

The connection to https://github.com/flatcar/ is more visible. Maybe with a "banner" or "sash" on the top right of the page. Other projects have a Icon with "GitHub" written besides it. Check https://k3s.io for an example.