[gtk/matthiasc/for-master] gtk-demo: Add more detail to the dnd demo text

[Matthias Clasen <matthiasc src gnome org>]

commit 50400879e0268fd9910d3dac272a968073ab4362
Author: Matthias Clasen <mclasen redhat com>
Date:   Mon Sep 14 17:49:16 2020 -0400

    gtk-demo: Add more detail to the dnd demo text

 demos/gtk-demo/dnd.c | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/demos/gtk-demo/dnd.c b/demos/gtk-demo/dnd.c
index 83e6e92359..2cdca577d9 100644
--- a/demos/gtk-demo/dnd.c
+++ b/demos/gtk-demo/dnd.c
@@ -1,8 +1,12 @@
 /* Drag-and-Drop
+ * #Keywords: dnd, menu, popover, gesture
  *
  * This demo shows dragging colors and widgets.
  * The items in this demo can be moved, recolored
  * and rotated.
+ *
+ * The demo also has an example for creating a
+ * menu-like popover without using a menu model.
  */
 
 #include <gtk/gtk.h>