Adds a steam locomotive & associated worse cargo wagon, which both use IR3 intermediates as ingredients.

The tech also unlocks rails, however does not unlock train stops. This is intended to be a balanced method of moving far away ores in an early game format, to remove the tedium of walking. Pretty much made this because on our dedicated server running IR3 we spawned super far away from iron, and want some form of bringing it back before green science (since you need iron to make green science).

The steam train uses IR3 steam cells as fuel.

Credits in readme.md for train model, scripting, and cargo wagon model.