doc: Remove optional containerName from README

Removed optional containerName parameter from configuration.

Author: andyzhangx

deploy/example/blobfuse-mi/README.md

@@ -37,7 +37,6 @@ AzureStorageIdentityClientID=`az identity list -g "$resourcegroup" --query "[?na
       protocol: fuse
       resourceGroup: EXISTING_RESOURCE_GROUP_NAME   # optional, node resource group by default if it's not provided
       storageAccount: EXISTING_STORAGE_ACCOUNT_NAME # optional, a new account will be created if it's not provided
-      containerName: EXISTING_CONTAINER_NAME  # optional, a new container will be created if it's not provided
       AzureStorageAuthType: MSI
       AzureStorageIdentityClientID: "xxxxx-xxxx-xxx-xxx-xxxxxxx"
     reclaimPolicy: Delete