On the Docker website I see mention of Docker on "bare metal". Does this mean that you can run Docker on hardware with no underlying OS?
If so, how would one install/implement it?
Yes, the bare metal in the docs refers to a server that is not in a hypervisor or "cloud server". But running on bare metal.
However if you are interested there has been this experiment as running docker as PID 1 https://github.com/ibuildthecloud/only-docker