PR review: Update region-availability-maas.md

Add "references_regions" to ms.custom metadata

Author: AnnaMHuff

articles/ai-studio/includes/region-availability-maas.md

@@ -7,7 +7,7 @@ ms.author: scottpolly
 ms.service: azure-ai-studio
 ms.topic: include
 ms.date: 08/05/2024
-ms.custom: include
+ms.custom: include, references_regions
 ---
 
 ### Cohere models