bug#43633: 28.0.50; Include definitions in glossary for: extensible, customizable, self-documenting, real-time display editor

[Eli Zaretskii]

> From: Richard Stallman <rms@gnu.org>
> Date: Sat, 26 Sep 2020 22:42:47 -0400
> Cc: 43633@debbugs.gnu.org
> 
>   > Emacs is the extensible, customizable, self-documenting real-time
>   > display editor.
> 
> Are there any editors in widespread use that are not real-time and
> display?  I know some still exist -- for instance, ed -- but perhaps
> it is no longer useful to say "real-time display" in that sentence.

The manual text (in "Intro") no longer says "real-time", that was only
left in the sentence that starts the Top node.  I've now made that say
the same as Intro does.