Document Scratch tutorials and their requirements

[bennorth]

The Scratch site has a collection of embedded tutorials which lead the learner through various features of the Scratch system. (Accessible by going to the main project editor, and clicking on the [light-bulb] tutorials button at the top.) We should look through them, and see if any would be useful illustrations of how Pytch works. Also, they might highlight features of Scratch which we should implement in Pytch.