- fix shuttle model to recalculate inertia matrix after centering
- refactor 3d plotting functions
- add functions for using quaternions
- add quaternion based model for integrating thrusts
- add exponential map based model for integrating thrusts
- refactor state space models for approximately maintaining constraints
- add euler step function
- add animation function for 3d

- add example of visualizing shuttle model
- add finding for inertia matrix and other mass properties
- add function to draw surface normals
- add function to draw thrusters
- refactor vis naming