Improvements to HW1a (Pokémon)

[gdalle]

• [ ] Invite students to use the documentation (? in the REPL / docs tab in Pluto)
• [ ] Present intro tutorial before the homework
• [ ] Say that just because checks are passing doesn't mean the answer is correct
• [ ] Add question numbers
• [ ] Explain what an empty struct means + how to compare mutable and immutable structs (== vs ===)
• [ ] Clarify inner / outer constructors
• [ ] Note on matrix indexing to prevent them from using linear indices
• [ ] Give a reference for various kinds of type dispatch syntax (f(x::X) vs f(x::Y) where {Y<:X})
• [ ] Specify expected output for attack(::Corgi, ::Pokemon), and state that we do not accept catch-all methods (code should rely on dispatch instead)
• [ ] Define what we mean by method ambiguity and explicitly lead students to find and resolve it
• [ ] Fix check_defense_philip check
• [ ] Explain how boundaries should be handled in the step! function
• [ ] Make it clear that the attacker cannot attack itself

[alanedelman]

We must have a yamper as well as a philip