bug#50894: Disable show-paren-mode in special modes

[Eli Zaretskii]

> From: Juri Linkov <juri@linkov.net>
> Cc: 50894@debbugs.gnu.org
> Date: Wed, 29 Sep 2021 22:54:20 +0300
> 
> >> So here is a new request created from bug#50881.
> >
> > Sorry, but I object to turning show-paren-mode off just 5 min after we
> > turned it on.  Please wait for a month at least before reporting
> > problems with that setting that are not clear bugs.
> 
> If you read a book where every paren is emphasized,
> what would you think about the author?

It doesn't matter what I think.  If I don't like that, I can turn it
off.

Moreover, some special modes display code fragments, where
show-paren-mode is definitely useful, especially to newbies who don't
yet have parenthesis peeling off burnt into their brains.  Even *Help*
buffers show code fragments.

Please, just let this feature alone for a while.  Disable it in your
customizations if you cannot stand it.  We can come back to it later,
when we have enough experience collected from those who will see this
default for the first time when Emacs 28.1 is released.  They are
those for whom we made this change, so let's hear their opinions
before changing anything.  My personal experience suggests that at
least some of them will have no problems where you see them.