[gtk+] revealer: Add CSS node docs

[Matthias Clasen <matthiasc src gnome org>]

commit f0a2f9ef965f113aafb66f4c702503444816d08a
Author: Matthias Clasen <mclasen redhat com>
Date:   Mon Dec 7 22:57:34 2015 -0500

    revealer: Add CSS node docs

 gtk/gtkrevealer.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkrevealer.c b/gtk/gtkrevealer.c
index 496ffe2..946f043 100644
--- a/gtk/gtkrevealer.c
+++ b/gtk/gtkrevealer.c
@@ -44,6 +44,10 @@
  * These animations respect the #GtkSettings:gtk-enable-animations
  * setting.
  *
+ * # CSS nodes
+ *
+ * GtkRevealer has a single CSS node with name revealer.
+ *
  * The GtkRevealer widget was added in GTK+ 3.10.
  */