bug#30685: end-of-file mode should respect read-only mode

[Eli Zaretskii]

> From: 積丹尼 Dan Jacobson <jidanni@jidanni.org>
> Cc: 30685@debbugs.gnu.org
> Date: Wed, 07 Mar 2018 04:35:15 +0800
> 
> >>>>> "EZ" == Eli Zaretskii <eliz@gnu.org> writes:
> EZ> If the user had Read the Fine Manual...
> 
> (info "(emacs) Misc Buffer")
> A buffer can be “read-only”, which means that commands to change its
> contents are not allowed.
> 
> So add:
> 
> "'Contents' do not include end-of-line conventions. There is currently
> no way to protect against them getting changed."

I clarified this in a different way.

Thanks.