Recreates the Quadtree Tree part 3 video (code)but trying to update and existing quadtree every frame instead of replacing it. Seems to work!

1. Rewrite quadtree to take an object instead of values, which I had hoped to avoid.
2. Created a Particle class and a ParticleSet class that required learning about function binding, named function notation and a note to self to look into arrow expressions
3. This project does not have a Circle class, it adds inscribed circle checking to Bounds and distance comparisons to Particle.