Create EX_*.3 manual page links to sysexits.3
Thank you very much for taking the charge in cleaning up manpages, etc!
FWIW, I don't think it would be a good idea to document individual error codes. We don't have manpage links for EINVAL.2, etc, to errno(2).
As long as we're consistent with POSIX's documentation, I believe we're ok with the status quo, which is leaving the individual error codes documented only in sysexits(3).