docs: install: Added Ubuntu and Fedora dependency installation lines
docs: todo: shorten todo entry, thanks to Jon

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
configs/ether.conf: Add ethertype for PRP Supervision

Ethertype used for supervision frames in IEC 62439 Parallel Redundancy
Protocol (PRP).

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>