bug#3447: suggest minibuffer M-< go to start of text

[Eli Zaretskii <eliz@gnu.org>]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: user42@zip.com.au,  3447@debbugs.gnu.org
> Date: Tue, 01 Oct 2019 13:58:22 +0200
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > As an opt-in behavior, please.  We can make it the default later, if
> > there's enough demand.
> 
> I can do that, but after using this for a bit, it just seems like very
> natural behaviour, which makes me wonder whether anybody really enjoys
> the previous behaviour.  I mean, there's very little of use you can do
> before the end of the minibuffer prompt.  The only use case I can see is
> if you want to copy the entire buffer contents to the kill ring...
> but...  how often is that done?

I understand that this is your impression, but that's just a single
person's impression.  The change in behavior is not insignificant.

> Perhaps we could just do the change below (calling it out in NEWS) and
> see whether anybody complains?  And if they do, we'll introduce the
> variable.

The problem with the complaints is that they usually come only after
Emacs is released, and by that time it is too late.  So let's have the
defcustom, please.