docs: update readme for expired links

Author: zoowii

README.md

@@ -104,7 +104,7 @@ The IR is still under development. Contributions are always welcome. Please foll
 ![wechat group](./assets/wx.png)
 -->
 
-![dingtalk group](./assets/dingtalk.png)
+<!-- ![dingtalk group](./assets/dingtalk.png) -->
 
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 * Join us on the [Discord]()