Update read-from-secret.md

Author: andyzhangx

docs/read-from-secret.md

@@ -1,18 +1,20 @@
 # Read cloud config from Kubernetes secrets
 
-- Available driver version: `v0.5.0` or above
+- available driver version: `v0.5.0` or above
 
 This driver also supports [reading the cloud config from Kubernetes secrets](https://github.com/kubernetes-sigs/cloud-provider-azure/blob/master/docs/cloud-provider-config.md#setting-azure-cloud-provider-from-kubernetes-secrets). The secret is a serialized version of `azure.json` file with key cloud-config. The secret should be put in `kube-system` namespace and its name should be `azure-cloud-provider`.
 
-### How to convert cloud config to a Kubernetes secret 
-1.  create `azure.json` file and fill in all necessary fields, refer to [Cloud provider config](https://github.com/kubernetes-sigs/cloud-provider-azure/blob/master/docs/cloud-provider-config.md), and here is an [example](https://github.com/andyzhangx/demo/blob/master/aks-engine/deployment/etc/kubernetes/azure.json)
+### How to convert cloud config to a Kubernetes secret
 
+1. create `azure.json` file and fill in all necessary fields, refer to [Cloud provider config](https://github.com/kubernetes-sigs/cloud-provider-azure/blob/master/docs/cloud-provider-config.md), and here is an [example](https://github.com/andyzhangx/demo/blob/master/aks-engine/deployment/etc/kubernetes/azure.json)
 2. serialize `azure.json` by following command:
+
 ```console
 cat azure.json | base64 | awk '{printf $0}'; echo
 ```
 
 3. create a secret file(`azure-cloud-provider.yaml`) with following values and fill in `cloud-config` value produced in step#2
+
 ```yaml
 apiVersion: v1
 data:
@@ -25,6 +27,19 @@ type: Opaque
 ```
 
 4. Create a `azure-cloud-provider` secret in k8s cluster
+
 ```console
 kubectl create -f azure-cloud-provider.yaml
 ```
+
+### specify different cloud config secret in driver deployment
+- available driver version: `v1.4.0` or above
+- set `cloudConfigSecretName`, `cloudConfigSecretNamesapce` in driver deployment, follow [helm chart guide](../charts/README.md#tips)
+```yaml
+        - name: blob
+          ...
+          args:
+            ...
+            - "--cloud-config-secret-name={{cloudConfigSecretName}}"
+            - "--cloud-config-secret-namespace={{cloudConfigSecretNamespace}}"
+```