Add RGB spheres animation

[NeunEinser]

This adds a script that will simulate RGB spheres.

3 spheres are created. Each of the 3 spheres represents one of the RGB primary colors.

During the initialization, the origin of each sphere is chosen such that they are approximately as far away from each other as possible.
Each origin will be at one of the given LED coordinates.

The sphere’s radii will increase and decrease during the animation. The initial radius is chosen at random for each sphere.
For each enlarge or shrinking cycle, the green sphere uses 120 animation frames the red sphere uses 160 frames, and the blue sphere uses 200 frames

Each RGB color component is calculated using the distance to the corresponding sphere. Specifically, the formular used is 255 * (1 - dist / max_dist) ^ 3, where max_dist is the maximum distance any of the LED can have from the sphere.

The sphere changes from enlarging to shrinking, when the current radius is approximately equal to its max_dist.
It switches back to enlarging, once its current radius is approximately 0.

I tested this already using the simulator provided in #5.

[oliverdunk]

Hey @NeunEinser! Matt asked if I could help with maintaining this repository, so I've been thinking about how best to do that. I've decided to create an examples folder where we can add contributions like this one - you can find some more information in the README.

Would you be up for updating your PR, to move your effect in to the examples folder?

[NeunEinser]

Sure :)

[oliverdunk]

Thanks!