added undo/redo feature

rdraught-ui/examples/ai_debugger.rs

@@ -0,0 +1,19 @@
+use glib::ExitCode;
+use rdraught::draughts::DraughtsGame;
+use rdraught::{draughts::Piece, draughts::Player, position::Position};
+use rdraught_ui::run;
+use std::collections::HashMap;
+
+fn main() -> ExitCode {
+    let mut pieces = HashMap::<Position, Piece>::new();
+    pieces.insert(Position::new(2, 4), Piece::CrownedRedPawn);
+    pieces.insert(Position::new(5, 5), Piece::CrownedWhitePawn);
+    let game = DraughtsGame::new(
+        |p| match pieces.get(&p) {
+            None => Piece::NoPiece,
+            Some(piece) => *piece,
+        },
+        Player::Red,
+    );
+    run(game)
+}