fix slack url

Signed-off-by: wbc6080 <wangbincheng4@huawei.com>

README.md

@@ -111,7 +111,7 @@ If you need support, start with the [troubleshooting guide](./docs/troubleshooti
 -->
 
 If you have questions, feel free to reach out to us in the following ways:
-- [slack channel](https://app.slack.com/client/TDZ5TGXQW/C01EG84REVB/details)
+- [slack channel](https://kubeedge.io/docs/community/slack/)
 
 ## Contributing
 

README_zh.md

@@ -93,7 +93,7 @@ Sedna的安装文档请参考[这里](/docs/setup/install.md)。
 -->
 
 如果您有任何疑问，请以下方式与我们联系：
-- [slack channel](https://app.slack.com/client/TDZ5TGXQW/C01EG84REVB/details)
+- [slack channel](https://kubeedge.io/docs/community/slack/)
 
 
 ## 贡献

docs/index/quickstart.md

@@ -179,5 +179,5 @@ Sedna is an open source project and in the spirit of openness and freedom, we we
 You can get in touch with the community according to the ways:
 * [Github Issues](https://github.com/kubeedge/sedna/issues)
 * [Regular Community Meeting](https://zoom.us/j/4167237304)
-* [slack channel](https://app.slack.com/client/TDZ5TGXQW/C01EG84REVB/details)
+* [slack channel](https://kubeedge.io/docs/community/slack/)