bug#50936: "(emacs) Help" does say how to find external packages

[Eli Zaretskii <eliz@gnu.org>]

> From: Stefan Kangas <stefan@marxist.se>
> Date: Fri, 1 Oct 2021 16:42:13 +0200
> Cc: 50936@debbugs.gnu.org
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > > That's a problem, but there is IMO no way around that as long as Emacs
> > > doesn't bundle packages like php-mode, haskell-mode, eglot or
> > > lsp-mode, markdown-mode, etc.
> >
> > I don't understand the relevance, please elaborate.
> 
> As a user, I come to "Help" to learn how to find more information on
> e.g. "I want indentation for Haskell code", or "how to enable syntax
> highlighting for Markdown".  The answer to many such questions is that
> you need to look for and install an external package.

The manual explains what is available in Emacs.  If the user looks for
features not in Emacs, it is okay not to find them in our
documentation.  It is unrealistic for use to provide ways to find
features outside of Emacs, because they are too many.  What if the
user is after something that's not on ELPA?

When we figure out how to more closely integrate with ELPA, we should
as part of that try to find ways of searching the documentation of
those packages as part of our "normal" Help commands.  But until we
have done that, I see no reason to make that section in the manual
less efficient just so we could say we are more complete.  I think
doing so will result in net loss.