Quiescence search

[mateusz2173]

• [ ] Read https://www.chessprogramming.org/Horizon_Effect
• [ ] Read https://www.chessprogramming.org/Quiescence_Search
• [ ] Implement Quiescence search:
  • [ ] In search, instead dropping to evaluate at horizon (depth == 0), we run quiescence search
  • [ ] Quiescence search is negamax search which searches only capture moves (recursively).