doc/texi2pod: rework man inclusion logic

Ignore @c man begin ... @c man end comments, rely on @chapter for marking
the beginning of the various manual top level sections.

This allows us to write markup which is not dependent on the specific
texi2pod.pl implementation.

This change causes a few rendering issues, which will be fixed in further
patches.
(cherry picked from commit ca3d786227adf20f4e19809090c980d6d1109bf8)

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
1 file changed