bug#31311: 27.0; doc of `pcase'

[Eli Zaretskii]

> From: Michael Heerdegen <michael_heerdegen@web.de>
> Cc: drew.adams@oracle.com,  31311@debbugs.gnu.org
> Date: Sun, 29 Apr 2018 22:05:55 +0200
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > There's nothing special about this feature that should present
> > conceptual problems for documenting it well, any more than any other
> > advanced feature of which we have dozens in the ELisp manual.
> 
> >From the beginning people were divided about the usefulness and
> conception of the thing, and people discussed exceptionally emotionally
> and destructively.

Irrelevant.  We are talking about documentation, not about the feature
itself.  The concept of how such complex features should be documented
is well established in Emacs, and we have a wealth of examples in the
ELisp manual of how it should be and is done.