bug#72798: 29.4; Documentation issues with Supercite re. filladapt

[Eli Zaretskii <eliz@gnu.org>]

> From: Marc Fargas <telenieko@telenieko.com>
> Date: Sat, 24 Aug 2024 23:29:33 +0200
> 
> In particular, on the /Filling Cited Text/ and /What Supercite Does/
> sections:
> 
> There are mentions to some "gin-mode" which I'm not sure it exists
> anymore. The only thing I found is some FTP archive [1] with a file
> "gin-mode.el" dated May 1989. I am attaching it here for reference.

I removed the reference to gin-mode.

> Then there are mentions to filladapt which is on ELPA, but enabling it
> breaks supercite,
> 
>     (use-package supercite
>       :ensure nil ; emacs builtin
>       :hook ((mail-citation . sc-cite-original)))
> 
>     (use-package filladapt			; better auto fill
>       :ensure t
>       :demand t
>       :config
>       (setq-default filladapt-mode t))
> 
> Now attempting to reply an email will output an error in *Messages* and
> citing will stop at the first paragraph:
> 
>     message-newline-and-reformat: This command only works in the body of the message
> 
> The manual tells you about "(sc-setup-filladapt)" but this function
> seems to be broken:
> 
>     Debugger entered--Lisp error: (void-variable filladapt-prefix-table)
>       sc-setup-filladapt()
>       eval-expression((sc-setup-filladapt) nil nil 127)
>       funcall-interactively(eval-expression (sc-setup-filladapt) nil nil 127)
>       command-execute(eval-expression)

Adding Kyle, in the hope that he will have some suggestions about this
aspect.