add CSI driver in readme

README.md

@@ -91,6 +91,10 @@ After that you can access the volume just like a local directory.
 
 To get all options, just run `./juicefs mount -h`.
 
+### Kubernetes
+
+There is a [Kubernetes CSI driver](https://github.com/juicedata/juicefs-csi-driver) to use JuiceFS in Kubernetes easily.
+
 ## POSIX Compatibility
 
 JuiceFS passed all of the 8813 tests in latest [pjdfstest](https://github.com/pjd/pjdfstest).

README_CN.md

@@ -90,6 +90,11 @@ $ ./juicefs mount -d localhost ~/jfs
 
 挂载之后你可以像使用本地盘一样使用它，详细的挂载参数，请运行 `./juicefs mount -h`。
 
+
+### Kubernetes
+
+JuiceFS 提供 [K8S CSI 驱动](https://github.com/juicedata/juicefs-csi-driver) 来简化部署.
+
 ## POSIX 兼容性测试
 
 JuiceFS 通过了 [pjdfstest](https://github.com/pjd/pjdfstest) 最新版所有 8813 项兼容性测试。