Updated negraph docs

Author: alexandrutomescu

docs/node-expanded-digraph.md

@@ -2,6 +2,8 @@
 
 If your graph has flow values or weights associated with the nodes, instead of the edges, we provide a simple way to handle them, via the class `NodeExpandedDiGraph`, as described below. 
 
+See [this example](https://github.com/algbio/flowpaths/blob/main/examples/node_weights_flow_correction.py) on how to correct weights on node-weighted graphs, support subpath constraints, and then apply Minimum Flow Decomposition on them.
+
 ::: flowpaths.nodeexpandeddigraph
     options:
       filters: 

examples/node_weights_flow_correction.py

@@ -22,13 +22,13 @@ def process_expanded_solution(neGraph: fp.NodeExpandedDiGraph, model: fp.MinFlow
 graph.add_node("d", flow=2)
 graph.add_node("t", flow=20)
 
-# We edges (notice that we do not add flow values to them)
+# We add graph edges (notice that we do not add flow values to them)
 graph.add_edges_from([("s", "a"), ("s", "b"), ("a", "b"), ("a", "c"), ("b", "c"), ("c", "d"), ("c", "t"), ("d", "t")])
 
-# We create a node expanded graph, where the weights are taken from the attribute "flow"
+# We create a node-expanded graph, where the weights are taken from the attribute "flow"
 neGraph = fp.NodeExpandedDiGraph(graph, node_flow_attr="flow")
 
-# We correct the graph
+# We correct the node-expanded graph
 correction_model = fp.MinErrorFlow(
     neGraph, 
     flow_attr="flow",
@@ -41,8 +41,8 @@ def process_expanded_solution(neGraph: fp.NodeExpandedDiGraph, model: fp.MinFlow
 subpath_constraints=[[('a', 'c'), ('c', 't')]]
 
 # We solve the problem on the corrected_neGraph 
-# NOTE: we are using edges_to_ignore from the original neGraph
-# NOTE: we are using subpath_constraints from the original neGraph
+# NOTE: we are using `edges_to_ignore` from the uncorrected neGraph
+# NOTE: we are using `subpath_constraints` from the uncorrected neGraph
 ne_mfd_model_edges = fp.MinFlowDecomp(
     corrected_neGraph,
     flow_attr="flow",