Add Content: Create a Game Board Challenge

[BrooklinJazz]

input: correct and incorrect answers

Original inspiration from @alena's game:

%{
 instruction: "Numbers 3 or below",
 correct: [1, 2, 3],
 incorrect: [4, 5, 6]
}

The result is a game board matrix:

[
[2, 4, 1], 
[3, nil, nil],
[nil, 5, 6]
]