Window(fix[move_window]): -r is standalone renumber, not renumber-after-move

why: In tmux's cmd-move-window.c, the -r flag triggers session_renumber_windows()
and returns CMD_RETURN_NORMAL immediately — the move logic on subsequent lines
is never reached. The docstring incorrectly said "Renumber all windows after
moving" implying both a renumber and a move occur.
what:
- Fix docstring to document -r as a standalone operation
- Note that other parameters are ignored when renumber is used

Author: tony

src/libtmux/window.py

@@ -969,7 +969,9 @@ def move_window(
 
             .. versionadded:: 0.45
         renumber : bool, optional
-            Renumber all windows after moving (``-r`` flag).
+            Renumber all windows in sequential order (``-r`` flag). This is a
+            standalone operation — when used, no move is performed and other
+            parameters are ignored.
 
             .. versionadded:: 0.45