Document well-known runtime hosts that `azd` consumes

[wbreza]

azd communicates with the ARM control plane and many other hosts during the execution of commands.

azd should provide a concrete list of well-known hosts that are required for azd to run to support use cases when azd is running behind a firewall or other networking appliances that filter internet traffic.

Examples:

• ARM management APIs for all clouds
• Telemetry collection
• Experimentation
• CLI tools including github, etc
• Customer URLs including their own app urls for application publishing
• ...