update wechat link

README.md

@@ -19,9 +19,7 @@ It offers an advanced Container Network Fabric for Enterprises with the most fun
 The Kube-OVN community is waiting for your participation!
 - Follow us at [Twitter](https://twitter.com/KubeOvn)
 - Chat with us at [Slack](https://kube-ovn-slackin.herokuapp.com/)
-- 微信用户扫码加入交流群
-
-  ![Image of wechat](./docs/wechat.png)
+- 微信用户请[填写表单](https://ma.alauda.cn/p/0f39a)加入交流群！
 
 ## Features
 - **Namespaced Subnets**: Each Namespace can have a unique Subnet (backed by a Logical Switch). Pods within the Namespace will have IP addresses allocated from the Subnet. It's also possible for multiple Namespaces to share a Subnet.