Update docs changelog (for PR #57395) (#57503)

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: hubwriter <[email protected]>
Co-authored-by: Sophie <[email protected]>

Author: 4 people

CHANGELOG.md

@@ -2,6 +2,14 @@
 
 **11 September 2025**
 
+Copilot Chat in VS Code includes a "Manage models" option which allows you to add models from a variety of LLM providers, such as Azure, Anthropic, Google, and xAI. By installing the AI Toolkit for VS Code, you can install even more models from the "Manage models" option. We've updated the documentation to include details of how to use this new feature.
+
+See [Changing the AI model for GitHub Copilot Chat](https://docs.github.com/en/copilot/how-tos/use-ai-models/change-the-chat-model?tool=vscode).
+
+<hr>
+
+**11 September 2025**
+
 You can now enable automatic Copilot code review with its own standalone repository rule. We've updated the documentation accordingly.
 
 See [Configuring automatic code review by GitHub Copilot](https://docs.github.com/copilot/how-tos/use-copilot-agents/request-a-code-review/configure-automatic-review).