Further explain 'by connections' vs 'by synapses' in docstrings

bluepysnap/edges/edge_population_stats.py

@@ -15,6 +15,11 @@ def __init__(self, edge_population):
     def divergence(self, source, target, by, sample=None):
         """`source` -> `target` divergence.
 
+        Calculate the divergence based on number of `"connections"` or `"synapses"` each `source`
+        cell shares with the cells specified in `target`.
+        * `connections`: number of unique target cells each source cell shares a connection with
+        * `synapses`: number of unique synapses between a source cell and its target cells
+
         Args:
             source (int/CircuitNodeId/CircuitNodeIds/sequence/str/mapping/None): source nodes
             target (int/CircuitNodeId/CircuitNodeIds/sequence/str/mapping/None): target nodes
@@ -48,6 +53,11 @@ def divergence(self, source, target, by, sample=None):
     def convergence(self, source, target, by=None, sample=None):
         """`source` -> `target` convergence.
 
+        Calculate the convergence based on number of `"connections"` or `"synapses"` each `target`
+        cell shares with the cells specified in `source`.
+        * `connections`: number of unique source cells each target cell shares a connection with
+        * `synapses`: number of unique synapses between a target cell and its source cells
+
         Args:
             source (int/CircuitNodeId/CircuitNodeIds/sequence/str/mapping/None): source nodes
             target (int/CircuitNodeId/CircuitNodeIds/sequence/str/mapping/None): target nodes