Dev/decode my302 (#254)

This PR adds support for decoding digital data from the my320 test chip.
- Added BitOffset (strong type)
- Expand 24 to 32 bit 
- Python bindings for decoding my302
- Improved docs

docs/src/python/cluster/pyCluster.rst

@@ -0,0 +1,23 @@
+Cluster
+========
+
+.. py:currentmodule:: aare
+
+.. autoclass:: Cluster
+    :members:
+    :undoc-members:
+    :inherited-members:
+
+
+Below is the API of a cluster of size :math:`3\times 3` and type ``int`` but all variants share the same API.
+
+    .. autoclass::  aare._aare.Cluster3x3i
+        :special-members: __init__
+        :members:
+        :undoc-members:
+        :show-inheritance:
+        :inherited-members:
+
+.. note:: 
+    More functions can be found in the :ref:`ClusterVector <py_clustervector>` documentation. Generally apply functions directly on the ``ClusterVector`` instead of looping over individual clusters.
+