man: Add .TQ groff support macro

man: Add .TQ groff support macro

This introduces the .TQ groff macro.  Even though this can be found
in newer groff versions, not all platforms we support carries this one.

This macro makes it possible to have mulitple lines of options as
headers before describing all of these options in the same segment.

Signed-off-by: David Sommerseth <davids@openvpn.net>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20180228131918.12954-1-davids@openvpn.net>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg16575.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
(cherry picked from commit 5ed5ac5cf869c0284ffeedda358da23e201357cc)