Update Square::Options to Marks and index at 1.

src/validator.rs

@@ -53,7 +53,7 @@ pub fn validate_board(board: &Board) -> BoardState {
     }
 
     if board.squares.iter().any(|sq| match sq {
-        Square::Options(_) => true,
+        Square::Marks(_) => true,
         _ => false,
     }) {
         BoardState::InProgress