Add a pre-defined seed option without the need for a template

[Dragnier]

Your mod does almost everything I need. However, I was wondering if you could add an option to define the default world seed rather than needing to add a template? Including a template world in a modpack just to get the right seed makes the file much larger than it needs to be. The only reason to use a template is to include custom building in the world and a default seed option would be useful when that isn't needed.