Fixed all H2 headings

Before, H2 fomratting was not consistent.
Now, all H2 headings use over/under asterisks.

docs/scenarios/serialization.rst

@@ -5,8 +5,10 @@ Data Serialization
 
 .. image:: /_static/photos/33467946364_3e59bd376a_k_d.jpg
 
+
+***************************
 What is data serialization?
----------------------------
+***************************
 
 Data serialization is the concept of converting structured data into a format
 that allows it to be shared or stored in such a way that its original
@@ -14,8 +16,10 @@ structure to be recovered. In some cases, the secondary intention of data
 serialization is to minimize the size of the serialized data which then
 minimizes disk space or bandwidth requirements.
 
+
+******
 Pickle
-------
+******
 
 The native data serialization module for Python is called `Pickle
 <https://docs.python.org/2/library/pickle.html>`_.
@@ -35,8 +39,10 @@ Here's an example:
         #Use loads to de-serialize an object
         received_grades = pickle.loads( serial_grades )
 
+
+********
 Protobuf
---------
+********
 
 If you're looking for a serialization module that has support in multiple
 languages, Google's `Protobuf