Add Steam Datagram Relay as a feature to the feature list on the store page

[Ettanin]

Peer-to-Peer multiplayer games suffer from connectivity deficiencies if the players only have a shared IPv4 address (CGNAT) or a shared IPv4 address with a public IPv6 address (Dual Stack Lite). There are still games that do not support direct IPv6 connections.

Valve has added a solution called Steam Datagram Relay: https://partner.steamgames.com/doc/features/multiplayer/steamdatagramrelay to allow people with limited IPv4 connectivity to connect together, using the Steam network as a tunneling relay.

It would be good if multiplayer games that make use of SDR would have that listed as a feature on their store pages because that would help players identify whether the netcode would be compatible to their type of internet access.