change explorer to workbench

Author: peze

README.md

@@ -20,7 +20,7 @@ Alibaba Cloud Client for PHP is a client tool that helps PHP developers manage c
 [Troubleshoot](https://troubleshoot.api.aliyun.com/?source=github_sdk) Provide OpenAPI diagnosis service to help developers locate quickly and provide solutions for developers through `RequestID` or `error message`.
 
 ## Online Demo
-[API Explorer](https://api.aliyun.com) provides the ability to call the cloud product OpenAPI online, and dynamically generate SDK Example code and quick retrieval interface, which can significantly reduce the difficulty of using the cloud API.
+[API Developer Portal](https://next.api.aliyun.com) provides the ability to call the cloud product OpenAPI online, and dynamically generate SDK Example code and quick retrieval interface, which can significantly reduce the difficulty of using the cloud API.
 
 
 ## Prerequisites