Rethink level 0 quesitons

[emaj9]

We need a suite of problems below "fundamentals" (which is severely lacking.)

I can only really use coding cat effectively by week 3

we need a set of problems on basics, which contain NO starter code, but ask students to just implement functions using specific function names, parameter names, returns etc. Like implement "add", return x + y, things like this

we'll probably want to do this via static analysis of students' code

and in general the early questions need a lot more love