Progress on the training manual

Ok, the help page for machines has been a little tricky, but I got there. Detangling the hard coded stuff I put in to build multimachines was a bit hard, so I ended up building a dummy game to feed into the machines when I'm creating them in the training manual. I still need to add icons for input and output feeds, but it should now just be one bit of work that'll apply to both the real machines and the training ones.

I also spent some time fixing the image for cross over conveyors, since the misalignment was bothering me. I don't think I'll have time to animate the cross over belts or the turntable, but we'll see...