doc/options: clean up documentation for --proto and related options

doc/options: clean up documentation for --proto and related options

The family specific options were generally omitted.

Cc: David Sommerseth <openvpn@sf.lists.topphemmelig.net>
Signed-off-by: Frank Lichtenheld <frank@lichtenheld.com>
Acked-by: David Sommerseth <davids@openvpn.net>
Message-Id: <20220215145425.1989-1-frank@lichtenheld.com>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg23798.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
(cherry picked from commit ba9a07a69db3ddb63fceac05b92a000d9b1c805e)