fix spelling

Author: GitHubber17

articles/aks/azure-files-volume.md

@@ -132,7 +132,7 @@ Volumes:
 
 ## Mount options
 
-The default value for *fileMode* and *dirMode* is *0755* for Kubernetes version 1.9.1 and above. If using a cluster with Kuberetes version 1.8.5 or greater and statically creating the persistent volume object, mount options need to be specified on the *PersistentVolume* object. The following example sets *0777*:
+The default value for *fileMode* and *dirMode* is *0755* for Kubernetes version 1.9.1 and above. If using a cluster with Kubernetes version 1.8.5 or greater and statically creating the persistent volume object, mount options need to be specified on the *PersistentVolume* object. The following example sets *0777*:
 
 ```yaml
 apiVersion: v1