Placed Buildings for Demo Level

Didn't have time, though, to add the inputs/outputs. See this for that
reference:

https://docs.google.com/document/d/131zLD29E81l1x9OwhpveUBTqPMLOWBpiPNgAOx3CNiE/edit
(Note that we're just using custom inputs/outputs for all buildings; had
to rotate the level on its side)