Update toc.yml

Author: cmcclister

articles/iot-dps/toc.yml

@@ -272,6 +272,6 @@ items:
   - name: Service updates
     href: https://azure.microsoft.com/updates/?product=iot-hub
   - name: Technical case studies
-    href: https://microsoft.github.io/techcasestudies/#technology=IoT&sortBy=featured
+    href: https://microsoft.github.io/generative-ai-for-beginners/#/
   - name: Videos
     href: https://azure.microsoft.com/documentation/videos/index/?services=iot-hub