Dev/rosenblatttransform (#241)

- added rosenblatttransform 
- added 3x3 eta methods 
- interpolation can be used with various eta functions
- added documentation for interpolation, eta calculation 
- exposed full eta struct in python 
- disable ClusterFinder for 2x2 clusters 
- factory function for ClusterVector

---------

Co-authored-by: Dhanya Thattil <dhanya.thattil@psi.ch>
Co-authored-by: Erik Fröjdh <erik.frojdh@psi.ch>

python/src/bind_ClusterVector.hpp

@@ -120,12 +120,13 @@ void define_2x2_reduction(py::module &m) {
                 reduce_to_2x2(cv));
         },
         R"(
-        
         Reduce cluster to 2x2 subcluster by taking the 2x2 subcluster with 
-        the highest photon energy."
+        the highest photon energy.
+
         Parameters
-        ----------
-        cv : ClusterVector   
+
+        cv : ClusterVector (clusters are filled in row-major ordering starting at the top left. Thus for a max subcluster in the top left corner the photon hit is at the fourth position.)
+
         )",
         py::arg("clustervector"));
 }
@@ -142,11 +143,10 @@ void define_3x3_reduction(py::module &m) {
                 reduce_to_3x3(cv));
         },
         R"(
-        
-        Reduce cluster to 3x3 subcluster by taking the 3x3 subcluster with 
-        the highest photon energy."
+        Reduce cluster to 3x3 subcluster 
+
         Parameters
-        ----------
+        
         cv : ClusterVector   
         )",
         py::arg("clustervector"));