Update: update open an issur for new example

CONTRIBUTING_en.md

@@ -33,6 +33,8 @@ If you'd like a feature or new type of example that doesn't exist in AgentScope
 - How it should work
 - What problem it solves or what use case it demonstrates
 
+**Note**: If you want to contribute your own example, please also open an issue first to discuss your idea and avoid duplicate work.
+
 
 
 ## Contributing Code

CONTRIBUTING_zh.md

@@ -33,6 +33,8 @@
 - 它应该如何工作
 - 它解决了什么问题或演示了什么用例
 
+**注意**：如果您想贡献自己的示例，也请先开一个 issue 讨论您的想法，避免重复工作。
+
 
 
 ## 贡献代码