bug#67620: Better indent-rigidly prompt

[Eli Zaretskii]

> Date: Tue, 05 Dec 2023 18:55:45 +0800
> From: Dan Jacobson <jidanni@jidanni.org>
> Cc: 67620@debbugs.gnu.org
> 
> Thanks for fixing it. I was talking about when you're reading the 
> sentence and you get halfway through and then you start to think.
> 
> As far as documenting C-i,. Perhaps put in the docstring.

We don't document the bindings in doc strings, because users can
rebind commands, and then the doc string will be incorrect.

There are also technical problems with referring to a single binding
when a command has several ones.

So I think this aspect will remain the user's responsibility (the
Emacs manual explains that TAB and C-i are the same).