Document using ingress for game server access

[dgkanatsios]

Some game servers require HTTPS/TLS connections, for example WebSocket servers. This can be configured in a Thundernetes cluster if the Nodes have no Public IP and the access to the game servers is implemented using a Kubernetes ingress. We have implemented a proof of concept here: https://github.com/dgkanatsios/thundernetescontrib/tree/main/traefikingress

We should enhance this sample and document the feature on Thundernetes website.