and add a list of known-working PCI devices.
- For consistency throughout this man page also talk about C-Bus and
ISA adapters rather than cards.
- Add missing .Tn.
- Mention ifconfig(8) along with listing selectable media types.
- Add/un-comment hardware notes for the newly supported 'lebuffer'
variants (the transition from P/N 501-1860 to 501-1869 isn't a typo).
was thinking from the pcn(4) perspective instead of the le(4) one when
writing the former version as le(4) supports a superset of the chips
supported by pcn(4) and not the other way round.