MoSDeF Tutorials 0.0.0

Beginning changes for aiche 2018 (#13)

* Beginning changes for aiche 2018

The beginning of the effort to whip the MoSDeF
notebook into shape for the 2018 AIChE COMSEF
workshop.

* Edits to intro, units, and included links for markdown, signac

* Beginning of data structure exploration

* edits to overview

* Small changes and cleanup