Add turtle into the module index.
diff --git a/Doc/library/turtle.rst b/Doc/library/turtle.rst
index 7b8ced7..67064d1 100644
--- a/Doc/library/turtle.rst
+++ b/Doc/library/turtle.rst
@@ -2,6 +2,10 @@
 :mod:`turtle` --- Turtle graphics for Tk
 ========================================
 
+.. module:: turtle
+   :synopsis: Turtle graphics for Tk
+.. sectionauthor:: Gregor Lingl <gregor.lingl@aon.at>
+
 Introduction
 ============