Move some of Unit 1 to Unit 0.

[jdonwells]

Last year I was confused by Units 1 and 0 and where they fit. This year I see what is happening.

In Unit 0 we have them make an account. They must make an account because we want them to save and submit their work.

In Unit 1 we show them how to make an account.

In Unit 0 we require them to find blocks and work with scripts.

In Unit 1 we show them how to find blocks and work with scripts.

The room I am in this year is very hot. I need the students to stay awake. The first part of Unit 1 repeats Unit 0. That isn't helpful for keeping their heads off the desk.