Update azure-subscription-service-limits.md

correct H2 to proper H3
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cc: @tfitzmac

Author: austinmccollum

articles/azure-resource-manager/management/azure-subscription-service-limits.md

@@ -410,7 +410,7 @@ This section lists the most common service limits you might encounter as you use
 
 [!INCLUDE [sentinel-service-limits](../../../includes/sentinel-limits-machine-learning.md)]
 
-## Multi workspace limits
+### Multi workspace limits
 
 [!INCLUDE [sentinel-service-limits](../../../includes/sentinel-limits-multi-workspace.md)]