Fix capitalization in Key Vault section header

Author: ktoliver

articles/app-service/app-service-key-vault-references.md

@@ -93,7 +93,7 @@ If the secret version isn't specified in the reference, the app uses the latest
 
 The delay is because App Service caches the values of the Key Vault references and refetches them every 24 hours. Any configuration change to the app causes an app restart and an immediate refetch of all referenced secrets.
 
-## <a name = "source-app-settings-from-key-vault"></a> Understand source app settings from key vault
+## <a name = "source-app-settings-from-key-vault"></a> Understand source app settings from Key Vault
 
 To use a Key Vault reference, set the reference as the value of the setting. Your app can reference the secret through its key as normal. No code changes are required.