bug#70010: 30.0.50; completion-preview-mode behaves mode-local, but is global

[Eli Zaretskii]

> Cc: 70010@debbugs.gnu.org
> Date: Tue, 26 Mar 2024 22:49:04 +0100
> From:  Eshel Yaron via "Bug reports for GNU Emacs,
>  the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
> 
> All right, here's a patch that adds such a global variant.

Thanks, but please add a NEWS entry announcing this, and also mention
this variant in the user manual, where completion-preview-mode is
documented.