bug#24897: 24.5; doc for `M' in Dired

[Eli Zaretskii]

> Date: Fri, 11 Oct 2019 08:45:32 -0700 (PDT)
> From: Drew Adams <drew.adams@oracle.com>
> Cc: 24897@debbugs.gnu.org
> 
> >   Note that on MS-Windows only the `w' (write) bit is meaningful:
> >   resetting it makes the file read-only.  Changing any other bit
> >   has no effect on MS-Windows.
> 
> Yes, that's fine.
> 
> (And it's good to say that `w' is a write bit.)
> 
> 
> [But do we usually write "MS-Windows" or "MS Windows"?]

As written.