MAINTAINERS: add man-pages git trees

The maintainer uses both.

Link: https://lkml.kernel.org/r/20240117122257.2707637-1-pvorel@suse.cz


Signed-off-by: Petr Vorel <pvorel@suse.cz>
Reviewed-by: Alejandro Colomar <alx@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>