Add "biconnected" definitions to {node,edge}_bcc.py

pyrival/graphs/edge_bcc.py

@@ -60,6 +60,8 @@ def find_SCC(graph):
 """
 Given an undirected simple graph, find_BCC returns a list of lists 
 containing the edge biconnected components of the graph (i.e. no bridges).
+In a biconnected component, any two nodes are connected by at least two
+edge-disjoint paths.
 Runs in O(n + m) time.
 
 This algorithm is based on https://cses.fi/problemset/task/2177

pyrival/graphs/node_bcc.py

@@ -24,6 +24,8 @@
 """
 Given an undirected graph, find_BCC returns a list of lists containing the nodes 
 of the different node-biconnected components.
+Node-biconnected components are maximal subgraphs that cannot be disconnected
+by removing a single node.
 Note that a node belongs to multiple node-bccs iff it is an articulation point.
 """