N-body simulation

Test simulator deployment with n-body problem simulation, running on custom Sprig firmware ('Grips') and as a desktop simulator application for Windows, Linux, and MacOS (I haven't tested it on MacOS).

W - Move up
S - Move down
D - Move right
A - Move left

I - Speed up/normal time
K - Slow down/reverse time
L - Add mass at crosshairs
J - Remove previous mass

Sprig version handles mass trails differently to avoid high memory usage. It will crash if you try to place more than 47 masses. The simulator will be fine though.