Sphere ASCII animation

Project to procrastinate from Examen Philosoficum....

Largely inspired by this

Geometry

The sphere is generated with spherical coordinates.

As we can only see half of the sphere anyways, theta runs from [-\pi, 0] and \phi runs from [-\pi/2, \pi/2] creating a half sphere.

Illumination model

The code uses a [Phong illumination model] (https://en.wikipedia.org/wiki/Phong_reflection_model).