Allow to unscale the output window with a Ctrl-Alt-u hotkey

Signed-off-by: malc <av1474@comtv.ru>
diff --git a/qemu-doc.texi b/qemu-doc.texi
index 68a6842..2f566b6 100644
--- a/qemu-doc.texi
+++ b/qemu-doc.texi
@@ -241,6 +241,9 @@
 @item Ctrl-Alt-f
 Toggle full screen
 
+@item Ctrl-Alt-u
+Restore the screen's un-scaled dimensions
+
 @item Ctrl-Alt-n
 Switch to virtual console 'n'. Standard console mappings are:
 @table @emph