Allow passing a reason to the shutdown command (#6828)

* Allow passing a reason to the shutdown command

* unused

Author: Atakku

Resources/Locale/en-US/commands.ftl

@@ -386,7 +386,7 @@ cmd-restart-desc = Gracefully restarts the server (not just the round).
 cmd-restart-help = Usage: {$command}
 
 cmd-shutdown-desc = Gracefully shuts down the server.
-cmd-shutdown-help = Usage: {$command}
+cmd-shutdown-help = Usage: {$command} [<Reason>]
 
 cmd-saveconfig-desc = Saves the server configuration to the config file.
 cmd-saveconfig-help = Usage: {$command}

Robust.Server/Console/Commands/SysCommands.cs

@@ -30,7 +30,7 @@ sealed partial class ShutdownCommand : LocalizedCommands
 
         public override void Execute(IConsoleShell shell, string argStr, string[] args)
         {
-            _server.Shutdown(null);
+            _server.Shutdown(argStr[$"{Command} ".Length..].Trim());
         }
     }