started on first lesson materials

These are notes that I was thinking about typing live in class as we introduce the concepts. Students would be encouraged to follow along on their personal machines. They would be given time to try to work out each item labeled `TASK`.

Adjusting the material to fit in 16 hours over the course of 4 weeks. Our new motto can be "Enough to be dangerous" :)

This is a work in progress. I'd appreciate some early feedback from @christopheraden @nick-ulle.