bug#38818: Dired: mention deleting buffers, not just windows

[martin rudalics]

> At (info "(emacs) Dired Enter")
>
>     Typing ‘q’ (‘quit-window’) buries the Dired buffer, and deletes its
>     window if the window was created just for that buffer.
>
> Add:
>
>    To delete the buffer instead of just burying it, type "1 q".

We can add that typing "q" with a prefix argument will kill the
buffer, but I'm afraid we have no facility supplying ...

>    To make deleting the buffer the default instead of burying it, use
>    (setq ... ...)

... that.

>    Users might find this helps keeping their buffer-list free of old
>    dired buffers crowding.

martin