new wording

Author: sdgilley

articles/ai-studio/toc.yml

@@ -34,7 +34,7 @@ items:
       - name: "Part 1: Set up resources"
         href: tutorials/copilot-sdk-create-resources.md
         displayName: code,sdk
-      - name: "Part 2: Add data retrieval to a chat app"
+      - name: "Part 2: Create chat app with data retrieval"
         href: tutorials/copilot-sdk-build-rag.md
         displayName: code,sdk
       - name: "Part 3: Evaluate and deploy a chat app"