Added compatibility launch options menu — A Dark Forest Steam update #487952

We've added launch options!Now when you click 'launch' on Steam you'll have to deal with a launch options menu.Sorry!The good news is that there is a "always use this setting" option. If you press that one you'll never have to think about it again!What exactly are those launch options?Windows, MacOS, and Linux users can now choose whether to use Godot's Forward+ renderer (default option) or the compatibility renderer.We recommend the Forward+ renderer, but the compatibility renderer provides greater stability, especially on older or low-spec devices!If your version of A Dark Forest ever crashed on startup or mid-game we strongly recommend trying out the compatibility renderer option for a spell!