bug#59631: 29.0.50; [PATCH] New check-man target to check man pages for errors

[Eli Zaretskii]

> From: Stefan Kangas <stefankangas@gmail.com>
> Date: Sun, 27 Nov 2022 07:23:49 -0800
> 
> The attached patch adds a new check-man target to check our man pages
> for errors.  I know we prefer info over man, but why not.  It will catch
> mistakes, like using unknown macros, etc.
> 
> To test this, change a macro like ".B" to ".BBB" in doc/man/emacs.1 and
> run "make check-man".

Thanks, but I think it is better to have this as a script in admin/, not a
rule in the top-level Makefile.  Especially since it requires specialized
tools and setups.