Add article about Copilot and data handling (#56299)

Co-authored-by: Claire W <78226508+crwaters16@users.noreply.github.com>
Co-authored-by: hubwriter <hubwriter@github.com>

content/copilot/reference/ai-models/index.md

@@ -9,5 +9,5 @@ topics:
 children:
   - /supported-ai-models-in-copilot
   - /choosing-the-right-ai-model-for-your-task
+  - /how-copilot-serves-ai-models
 ---
-