Update concept-retrieval-augumented-generation.md

Author: luzhang06

articles/ai-services/document-intelligence/concept-retrieval-augumented-generation.md

@@ -119,7 +119,7 @@ If you're looking for a specific section in a document, you can use semantic chu
 
 ```python
 
-# Using SDK targeting 2023-10-31-preview
+# Using SDK targeting 2023-10-31-preview, make sure your resource is in one of these regions: East US, West US2, West Europe
 # pip install azure-ai-documentintelligence==1.0.0b1
 # pip install langchain langchain-community azure-ai-documentintelligence