Update README.md

Author: rl-msft

samples/features/sql-big-data-cluster/deployment/kubeadm/ubuntu/README.md

@@ -32,7 +32,7 @@ Simply type in "local-storage" twice (once for data, once for logs) when facing
 
 `Kubernetes Storage Class - Config Path: spec.storage.data.className - Description: This indicates the name of the Kubernetes Storage Class to use. You must pre-provision the storage class and the persistent volumes or you can use a built in storage class if the platform you are deploying provides this capability. - Please provide a value:`
 
-### local-storage Clean up
+### local-storage clean up
 
 If you removed BDC cluster that was previously deployed on Kubernetes cluster that was built using the sample scripts in this guide, you may want to clean the local-storage before using the cluster to deploy new BDC