[gtk+] gtk3-demo: Improve the overlay demo

[Matthias Clasen <matthiasc src gnome org>]

commit d6a52218d185cae483db11d7f9b46804034b4241
Author: Matthias Clasen <mclasen redhat com>
Date:   Fri Jun 19 20:08:15 2015 -0400

    gtk3-demo: Improve the overlay demo
    
    Add some more information to the description.

 demos/gtk-demo/overlay.c |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)
---
diff --git a/demos/gtk-demo/overlay.c b/demos/gtk-demo/overlay.c
index c39189e..f06da40 100644
--- a/demos/gtk-demo/overlay.c
+++ b/demos/gtk-demo/overlay.c
@@ -1,6 +1,10 @@
 /* Overlay
  *
- * Stack widgets in static positions over a main widget.
+ * Shows widgets in static positions over a main widget.
+ *
+ * The overlayed widgets can be interactive controls such
+ * as the entry in this example, or just decorative, like
+ * the big blue label.
  */
 
 #include <gtk/gtk.h>