[gtk+] docs: add docs for GtkIconSize

[William Jon McCann <mccann src gnome org>]

commit 212f6cef5e072532d584aeaa396cb5f615ddc004
Author: William Jon McCann <william jon mccann gmail com>
Date:   Tue Jan 21 12:26:55 2014 -0500

    docs: add docs for GtkIconSize

 gtk/gtkenums.h |   13 ++++++++++++-
 1 files changed, 12 insertions(+), 1 deletions(-)
---
diff --git a/gtk/gtkenums.h b/gtk/gtkenums.h
index 120f022..cc202bc 100644
--- a/gtk/gtkenums.h
+++ b/gtk/gtkenums.h
@@ -250,7 +250,18 @@ typedef enum
   GTK_EXPANDER_EXPANDED
 } GtkExpanderStyle;
 
-/* Built-in stock icon sizes */
+/**
+ * GtkIconSize:
+ * @GTK_ICON_SIZE_INVALID: Invalid size.
+ * @GTK_ICON_SIZE_MENU: Size appropriate for menus (16px).
+ * @GTK_ICON_SIZE_SMALL_TOOLBAR: Size appropriate for small toolbars (18px).
+ * @GTK_ICON_SIZE_LARGE_TOOLBAR: Size appropriate for large toolbars (24px)
+ * @GTK_ICON_SIZE_BUTTON: Size appropriate for buttons (20px)
+ * @GTK_ICON_SIZE_DND: Size appropriate for drag and drop (32px)
+ * @GTK_ICON_SIZE_DIALOG: Size appropriate for dialogs (48px)
+ *
+ * Built-in stock icon sizes.
+ */
 typedef enum
 {
   GTK_ICON_SIZE_INVALID,