[gtk+] Add an index for 3.22 api additions

[Matthias Clasen <matthiasc src gnome org>]

commit 8ef12fda83a53a4459840363d0e44306ca91b5a8
Author: Matthias Clasen <mclasen redhat com>
Date:   Sun Apr 3 23:33:57 2016 -0400

    Add an index for 3.22 api additions

 docs/reference/gdk/gdk-docs.sgml |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/docs/reference/gdk/gdk-docs.sgml b/docs/reference/gdk/gdk-docs.sgml
index fdd36a4..ac650ab 100644
--- a/docs/reference/gdk/gdk-docs.sgml
+++ b/docs/reference/gdk/gdk-docs.sgml
@@ -106,6 +106,10 @@
     <title>Index of new symbols in 3.20</title>
     <xi:include href="xml/api-index-3.20.xml"><xi:fallback /></xi:include>
   </index>
+  <index id="api-index-3-22" role="3.22">
+    <title>Index of new symbols in 3.22</title>
+    <xi:include href="xml/api-index-3.22.xml"><xi:fallback /></xi:include>
+  </index>
 
   <xi:include href="xml/annotation-glossary.xml"><xi:fallback /></xi:include>