Update README.md

Author: andyzhangx

README.md

@@ -26,8 +26,8 @@ Since `v0.7.0`, driver name changed from `blobfuse.csi.azure.com` to `blob.csi.a
 Please refer to `blob.csi.azure.com` [driver parameters](./docs/driver-parameters.md)
 
 ### Prerequisites
-#### Option#1: cloud provider config file
- - The driver depends on [cloud provider config file](https://github.com/kubernetes/cloud-provider-azure/blob/master/docs/cloud-provider-config.md), usually it's `/etc/kubernetes/azure.json` on all kubernetes nodes deployed by [AKS](https://docs.microsoft.com/en-us/azure/aks/) or [aks-engine](https://github.com/Azure/aks-engine), here is [azure.json example](./deploy/example/azure.json).
+#### Option#1: Provide Azure cendential with cloud provider config
+ - This option depends on [cloud provider config file](https://github.com/kubernetes/cloud-provider-azure/blob/master/docs/cloud-provider-config.md), usually it's `/etc/kubernetes/azure.json` on all Kubernetes agent nodes deployed by [AKS](https://docs.microsoft.com/en-us/azure/aks/) or [aks-engine](https://github.com/Azure/aks-engine), here is [azure.json example](./deploy/example/azure.json).
  > To specify a different cloud provider config file, create `azure-cred-file` configmap before driver installation, e.g. for OpenShift, it's `/etc/kubernetes/cloud.conf` (make sure config file path is in the `volumeMounts.mountPath`)
  > ```console
  > kubectl create configmap azure-cred-file --from-literal=path="/etc/kubernetes/cloud.conf" --from-literal=path-windows="C:\\k\\cloud.conf" -n kube-system