[bitboard] Add pawn attacks bitboards to the Library

bitboard/src/bitboard.rs

@@ -40,6 +40,10 @@ impl BitBoard {
         library().ray(sq, dir)
     }
 
+    pub fn pawn_attacks(sq: Square, color: Color) -> BitBoard {
+        library().pawn_attacks(sq, color)
+    }
+
     moves_getter!(knight_moves);
     moves_getter!(bishop_moves);
     moves_getter!(rook_moves);