examples+docs: Adding a new example to print out instantaneous PIT sizes periodically
diff --git a/docs/source/examples.rst b/docs/source/examples.rst
index e8bb522..be27f0b 100644
--- a/docs/source/examples.rst
+++ b/docs/source/examples.rst
@@ -313,3 +313,8 @@
 -----------------------------------
 
 :ref:`Example of packet drop tracer (L2Tracer)`
+
+3-node topology with periodic tracing of PIT
+--------------------------------------------
+
+:ref:`periodic tracing of Pending Interest Table (PIT) size`