Update csi-dev.md

Author: andyzhangx

docs/csi-dev.md

@@ -15,6 +15,11 @@ $ make blob
  - Run verification before sending PR
 ```console
 $ make verify
+```
+
+ - If there is config file changed under `charts` directory, run following command to update chart file.
+```console
+helm package charts/latest/blob-csi-driver -d charts/latest/
 ```
 
  - Build continer image and push to dockerhub