[gtk+] Document gtk_menu_place_on_monitor

[Matthias Clasen <matthiasc src gnome org>]

commit 8afb655347a3b09d874920812c0efa7568f78d35
Author: Matthias Clasen <mclasen redhat com>
Date:   Sat Nov 19 13:51:50 2016 -0500

    Document gtk_menu_place_on_monitor

 gtk/gtkmenu.c |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkmenu.c b/gtk/gtkmenu.c
index e345779..3a569f2 100644
--- a/gtk/gtkmenu.c
+++ b/gtk/gtkmenu.c
@@ -5215,6 +5215,15 @@ gtk_menu_get_monitor (GtkMenu *menu)
   return menu->priv->monitor_num;
 }
 
+/**
+ * gtk_menu_place_on_monitor:
+ * @menu: a #GtkMenu
+ * @monitor: the monitor to place the menu on
+ *
+ * Places @menu on the given monitor.
+ *
+ * Since: 3.22
+ */
 void
 gtk_menu_place_on_monitor (GtkMenu    *menu,
                            GdkMonitor *monitor)