readme updates

Author: aarora79

README.md

@@ -148,6 +148,7 @@ flowchart TB
 *   An Amazon EC2 machine (`ml.t3.2xlarge`) with a standard Ubuntu AMI for running this solution.
 *   An SSL cert for securing the communication to the Gateway. _This Gateway uses a self-signed cert by default and is also available over HTTP_. 
 *   One of the example MCP servers packaged in this repo uses the [`Polygon`](https://polygon.io/stocks) API for stock ticker data. Get an API key from [here](https://polygon.io/dashboard/signup?redirect=%2Fdashboard%2Fkeys). The server will still start without the API key but you will get a 401 Unauthorized error when using the tools provided by this server.
+*   Setup authentication using Amazon Cognito as per instructions [here](docs/auth.md).
 
 ## Installation