Defining a Mechanism Documentation out-of-date

[mfogelson]

As a new person to Julia these were some problems I encountered while working through the documentation.

When trying to create the Tippetop from the Documentation under "Defining a Mechanism" there are several functions that seem to be modified leading to errors and some information that could included for clarity:

1. Dependencies are unclear

• Must add LinearAlgebra for new mechanism to access Diagonal function
• gray_light is not exported by Dojo.jl Available color functions: cyan, orange, magenta
• Must import Dojo.set_minimal_coordinates_velocities!

2. Simulation does not match video

• The default values for initialize_tippetop! do not generate the cool spinning video, it would be nice if those parameters were included in the documentation as well.

[janbruedigam]

The docs should be up to date now, although some of the videos might be different from the current code version.
Feel free to reopen if there are issues.