readme headline casing

Author: toherman-msft

README.md

@@ -77,7 +77,7 @@ Follow the quick deploy steps on the deployment guide to deploy this solution
 
 <br/>
 
-### Prerequisites and Costs
+### Prerequisites and costs
 
 To deploy this solution accelerator, ensure you have access to an [Azure subscription](https://azure.microsoft.com/free/) with the necessary permissions to create **resource groups, resources, app registrations, and assign roles at the resource group level**. This should include Contributor role at the subscription level and  Role Based Access Control role on the subscription and/or resource group level. Follow the steps in [Azure Account Set Up](./docs/AzureAccountSetUp.md).
 
@@ -116,7 +116,7 @@ either by deleting the resource group in the Portal or running `azd down`.
 
 <br /><br />
 <h2><img src="./docs/images/readme/business-scenario.png" width="48" />
-Business Use Case
+Business use case
 </h2>