docs: Small update of the documentation

+ Adding reference to the used packet format to the TOC
diff --git a/docs/source/index.rst b/docs/source/index.rst
index 0a564d6..98c1f7b 100644
--- a/docs/source/index.rst
+++ b/docs/source/index.rst
@@ -19,4 +19,7 @@
    applications
    examples
    metric
+   ndnsim-packet-formats
    faq
+
+* :ref:`search`