[WIP] Update README to reference SECURITY.md per PR feedback (#213)

* Initial plan

* Update README to reference SECURITY.md at repository root

Co-authored-by: rbrighenti <202984599+rbrighenti@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: rbrighenti <202984599+rbrighenti@users.noreply.github.com>

Author: Copilot

nodejs/n8n/sample-agent/README.md

@@ -162,7 +162,7 @@ For issues, questions, or feedback:
 
 - **Issues**: Please file issues in the [GitHub Issues](https://github.com/microsoft/Agent365-nodejs/issues) section
 - **Documentation**: See the [Microsoft Agent 365 Developer documentation](https://learn.microsoft.com/en-us/microsoft-agent-365/developer/)
-- **Security**: For security issues, please see [SECURITY.md](SECURITY.md)
+- **Security**: For security issues, please see [SECURITY.md](../../../SECURITY.md)
 
 ## Contributing