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/pyClusterVector.rst

@@ -0,0 +1,58 @@
+.. _py_clustervector:
+    
+ClusterVector
+================
+
+The ClusterVector, holds clusters from the ClusterFinder. Since it is templated
+in C++  we use a suffix indicating the type of cluster it holds. The suffix follows
+the same pattern as for ClusterFile i.e. ``ClusterVector_Cluster3x3i``
+for a vector holding 3x3 integer clusters.
+
+
+At the moment the functionality from python is limited and it is not supported
+to push_back clusters to the vector. The intended use case is to pass it to 
+C++ functions that support the ClusterVector or to view it as a numpy array.
+
+**View ClusterVector as numpy array**
+
+.. code:: python
+
+    from aare import ClusterFile
+    with ClusterFile("path/to/file") as f:
+        cluster_vector = f.read_frame()
+
+    # Create a copy of the cluster data in a numpy array
+    clusters = np.array(cluster_vector)
+
+    # Avoid copying the data by passing copy=False
+    clusters = np.array(cluster_vector, copy = False)
+
+
+.. py:currentmodule:: aare
+
+.. autoclass:: ClusterVector
+    :members:
+    :undoc-members:
+    :inherited-members:
+
+Below is the API of the ClusterVector_Cluster3x3i but all variants share the same API.
+
+.. autoclass::  aare._aare.ClusterVector_Cluster3x3i
+    :special-members: __init__
+    :members:
+    :undoc-members:
+    :show-inheritance:
+    :inherited-members:
+
+
+**Free Functions:** 
+
+.. autofunction:: reduce_to_3x3
+   :noindex:
+
+   Reduce a single Cluster to 3x3 by taking the 3x3 subcluster with highest photon energy.
+
+.. autofunction:: reduce_to_2x2
+   :noindex:
+
+   Reduce a single Cluster to 2x2 by taking the 2x2 subcluster with highest photon energy.