Add links to 3.1 topological graphs

README.md

@@ -43,8 +43,11 @@ _In chronological order_
 This project adheres to the Contributor Covenant [code of conduct](CODE_OF_CONDUCT.md). By participating, you are expected to uphold this code. Please report unacceptable behavior to wu.sheng@foxmail.com.
 
 # Screenshots
-- Topological graph of application clusters.
-<img src="https://sky-walking.github.io/page-resources/3.0/topological_graph.png?forceUpdate=0"/>
+- Topological graph of application clusters based on dubbox and [motan](https://github.com/weibocom/motan).
+<img src="https://sky-walking.github.io/page-resources/3.1/topological_graph_test_project.png?forceUpdate=0"/>
+
+- Topological graph of application clusters based on Spring Cloud.
+<img src="https://sky-walking.github.io/page-resources/3.1/topological_graph.png?forceUpdate=0"/>
 
 - Trace query.
 <img src="https://sky-walking.github.io/page-resources/3.0/trace_segment.png"/>