Updating the Azure Front Door with ARO guide

[diana-sari]

Summary

This PR revamps the Azure Front Door with ARO guide and validates the workflow against a private ARO cluster.

The updated guide:

• Replaces the outdated Microsweeper and PostgreSQL example with a lightweight test application.
• Uses a dedicated subnet and Azure Private Link Service to connect Azure Front Door Premium to the private ARO ingress load balancer.
• Documents the current Azure Portal workflow for creating the Front Door endpoint, route, origin group, and origin.
• Adds the required origin host header configuration so OpenShift can match application Routes and health probes do not return 503.
• Adds validation, troubleshooting, cleanup steps, and guidance for publishing multiple application hostnames.

[aws-amplify-us-east-2]

This pull request is automatically being deployed by Amplify Hosting (learn more).

Access this pull request here: https://pr-960.dqokbbp7eqr35.amplifyapp.com