Add State struct as part of Board struct

src/game.rs

@@ -7,14 +7,12 @@ use String as FenError;
 #[derive(Debug, PartialEq, Eq)]
 pub struct Game {
     pub board: Board,
-    pub state: State,
 }
 
 impl Game {
     pub const fn new() -> Self {
         Self {
             board: Board::new(),
-            state: State::new(),
         }
     }
 
@@ -33,7 +31,7 @@ impl Default for Game {
     }
 }
 
-#[derive(Debug, PartialEq, Eq)]
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
 pub struct State {
     side_to_move: Color,
     castling_ability: u8,
@@ -68,6 +66,10 @@ impl State {
             fullmove_counter,
         }
     }
+
+    pub const fn get_en_passant_target_square(&self) -> u8 {
+        self.en_passant_target_square
+    }
 }
 
 use std::fmt;