update readme

README.md

@@ -8,6 +8,8 @@ observability, security, tools, and best practices for building enterprise-ready
 
 Dubbo-js is the TypeScript implementation of [Dubbo triple protocol (a fully gRPC compatible and http friendly protocol)](https://dubbo.apache.org/zh-cn/overview/reference/protocols/triple-spec/), which can be used for Node.js and web application development. With dubbo-js, you can easily build applications working on browser and frontend that can communicate with backend services through http-based protocol.
 
+[arc](./example/dubbo-web-example/doc/arc.png)
+
 * [Node.js Documentation](https://github.com/apache/dubbo-js/blob/dubbo3/example/dubbo-node-example)
 * [Web Documentation](https://github.com/apache/dubbo-js/blob/dubbo3/example/dubbo-web-example)