code: function intersects(a, b) {
  	return a.position[0] < b.position[0] + b.size[0] && a.position[0] + a.size[0] > b.position[0]
  	    && a.position[1] < b.position[1] + b.size[1] && a.position[1] + a.size[1] > b.position[1]
  }
docs: determines if box `a` and box `b` intersect