Function or_gadget 

pub fn or_gadget<W>() -> LogicGadget<W>
where
    W: Clone + Default + From<i32>,

Create an OR gate gadget.

3-variable SpinGlass: inputs at indices 0, 1; output at index 2. Ground states: (0,0,0), (0,1,1), (1,0,1), (1,1,1) corresponding to all valid OR truth table entries.

J = [1, -2, -2] for edges (0,1), (0,2), (1,2) h = [1, 1, -2] (negated from Julia to account for different spin convention)