update readme

Author: saibalmars

README.md

@@ -49,7 +49,7 @@ Video demonstration of Ricci flow for community detection:
 pip3 install [--user] GraphRicciCurvature
 ```
 
-- From version 0.4.0, in order to support larger graph, we switch to NetworKit's pairwise bidirectional dijkstra algorithm for density distribution (NetworKit>6.0 is required). If the installation of NetworKit failed, please refer to [NetworKit' Installation instructions](https://github.com/networkit/networkit#installation-instructions). In most of the cast build this package from source is recommended.
+- From version 0.4.0, NetworKit is required for density distribution (NetworKit>=6.1 is required). If the installation of NetworKit failed, please refer to [NetworKit' Installation instructions](https://github.com/networkit/networkit#installation-instructions). In most of the cast build this package from source is recommended.
 
 
 ## Getting Started