fix readme Configuration Tags for HDInsight (#12592)

Author: cataggar

specification/hdinsight/resource-manager/readme.md

@@ -32,7 +32,7 @@ azure-arm: true
 tag: package-2018-06-preview
 ```
 
-## Suppression
+### Suppression
 ``` yaml
 directive:
   - suppress: DefinitionsPropertiesNamesCamelCase