emacs-27 ed2b23e: Improve the 'dired-do-kill-lines' doc string

[Eli Zaretskii]

branch: emacs-27
commit ed2b23ecc10925b5b29ab13949a5d154c7d0cbe6
Author: Lars Ingebrigtsen <larsi@gnus.org>
Commit: Eli Zaretskii <eliz@gnu.org>

    Improve the 'dired-do-kill-lines' doc string
    
    * lisp/dired-aux.el (dired-do-kill-lines): Document the FMT
    parameter (bug#46867).
    
    (cherry picked from commit b9cb3b904008a80c69ab433f4851377967b100db)
---
 lisp/dired-aux.el | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/lisp/dired-aux.el b/lisp/dired-aux.el
index cef4de1..6c79081 100644
--- a/lisp/dired-aux.el
+++ b/lisp/dired-aux.el
@@ -954,8 +954,13 @@ Dired buffer as a subdirectory, then it deletes that 
subdirectory
 from the buffer as well.
 To kill an entire subdirectory \(without killing its line in the
 parent directory), go to its directory header line and use this
-command with a prefix argument (the value does not matter)."
-  ;; Returns count of killed lines.  FMT="" suppresses message.
+command with a prefix argument (the value does not matter).
+
+This function returns the number of killed lines.
+
+FMT is a format string used for messaging the user about the
+killed lines, and defaults to \"Killed %d line%s.\" if not
+present.  A FMT of \"\" will suppress the messaging."
   (interactive "P")
   (if arg
       (if (dired-get-subdir)