🔧 Add endpoint to expose all available endpoints

[FranklinWaller]

🔧 Chore

Have an extra endpoint /available(?) that shows all available endpoints set by the configuration file with a description.

{
    "routeGroup": "proxy",
    "routes": [
        {
            "path": "/something",
            "upstreamUrl": "myendpoint.com",
            "description": "Mirror of myendpoint.com/api see docs.myendpoint.com"
            "method": [
                "POST"
            ]
        }
    ]
}

Motivation

Easier for developers to see what is available. We should not expose upstreamUrl, headers, etc. Only path, description and method(s).