bug#46979: Allow setting Man-default-entry via Local Variables

[Eli Zaretskii]

> From: 積丹尼 Dan Jacobson <jidanni@jidanni.org>
> Cc: mardani29@yahoo.es,  46979@debbugs.gnu.org
> Date: Mon, 08 Mar 2021 22:48:51 +0800
> 
> C-h S, powerful as it may be, only seems to help with 5% of the points I
> have made.

That's enough to close the bug report from my POV.  But why only 5?
what real problems does it not handle, pray-say?