Add rigid body dynamics notebook.
Add example rgb figure and rough vector work.
Outline the rest of the RBD notebook.
Draft of dot product.
Add dot product macro.
Trying to make an html table to place figure beside equation.
Add vector figures.
Finish vector expression section.
Finish section on rotation matrices.
A few small things.
Finish reference frames.
Write velocity section.
Add missing figure.
Merge pull request #26 from chrisdembia/rigid-body-dynamics

Rigid body dynamics