Changed directory structure

include/camera.hpp

include/color.hpp

include/constant_deformer.hpp

include/deformer.hpp

include/dielectric.hpp

include/hittable.hpp

include/hittable_list.hpp

include/interpolating_deformer.hpp

include/linear_deformer.hpp

include/material.hpp

include/quadratic_deformer.hpp

include/quartic_deformer.hpp

include/radiator.hpp

include/ray.hpp

include/raytracing.hpp

include/triangle.hpp

include/triangle_mesh.hpp

include/vec3.hpp

include/wavelength2rgb.hpp

include/xyplane.hpp