kern/58056: sysctl(9) man page missing CTLFLAG_ANYNUMBER and examples section

[campbell+netbsd%mumble.net@localhost]

>Number:         58056
>Category:       kern
>Synopsis:       sysctl(9) man page missing CTLFLAG_ANYNUMBER and examples section
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          doc-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Mar 20 19:15:00 +0000 2024
>Originator:     Taylor R Campbell
>Release:        current
>Organization:
the.netbsd.foundation
>Environment:
>Description:
The CTLFLAG_ANYNUMBER is the magic way that sysctl proc.* works, but it's not obvious without digging into the guts of kern_sysctl.c sysctl_locate.  It should be documented.

Also there should be an EXAMPLES section in the man page to show some common example uses.  (And maybe we should have shorter idioms for some common examples.)
>How-To-Repeat:
man 9 sysctl
>Fix:
Yes, please!