src bug: Adding missing topology files

Wrong wildcard in gitignore prevented them to be commited earlier
diff --git a/docs/source/examples.rst b/docs/source/examples.rst
index f0485c3..7557f3c 100644
--- a/docs/source/examples.rst
+++ b/docs/source/examples.rst
@@ -268,6 +268,12 @@
 :ref:`cs trace helper example`
 
 
+3-level binary tree with  application-level Interest-Data delay tracer
+----------------------------------------------------------------------
+
+:ref:`app delay trace helper example`
+
+
 3-node topology with Content Store respecting freshness field of ContentObjects
 -------------------------------------------------------------------------------