Allows the selection of specific builds of a game server in SteamCMD
Game developers sometimes make available several builds of the game server on Steam, often to allow beta testing of new releases. These builds are made available via branches (betas) and can be entered in the LinuxGSM Config.
A list of all available branches for a game server are listed on SteamDB under the appid depots.
# Steam App Branch Select
# Example: "latest_experimental"