bug#55742: 29.0.50; Confusing "pcase" documentation on the web

[Eli Zaretskii <eliz@gnu.org>]

> Cc: 55742@debbugs.gnu.org
> From: Lars Ingebrigtsen <larsi@gnus.org>
> Date: Wed, 01 Jun 2022 15:39:55 +0200
> 
> Rudolf Adamkovič <salutis@me.com> writes:
> 
> > In "The pcase macro" documentation on the web
> >
> > https://www.gnu.org/software/emacs/manual/html_node/elisp/pcase-Macro.html
> >
> > has "_" on its own line, surrounded with whitespace.  It looks like a
> > dash, and in a graphical browser, one has to select it to discover the
> > mistake.  Could we add the word "underscore" somewhere next to it?
> 
> Yup.  The texi here is 
> 
> ---
> @table @code
> 
> @item _
> Matches any @var{expval}.
> This is also known as @dfn{don't care} or @dfn{wildcard}.
> ---
> 
> Anybody know whether we have a convention for adding notes/comments
> after a @code item?

Like this:

  @item _@r{ (underscore)}