- Remove issues that no longer apply thanks to devfs
- Add language pointing out devfs's role and referencing its config
- Add a "historical notes" section and move discussion of block vs character devs to it, including pointing out the removal of block devs
- Modernize some examples
MFC after: 1 week
PR: 236970
Submitted by: andrew@tao173.riddles.org.uk
Reviewed by: 0mp
Differential Revision: https://reviews.freebsd.org/D19799