[board] Refer to Position with $crate in the position! macro

board/src/position/position.rs

@@ -22,7 +22,7 @@ pub(crate) enum BoardSide {
 #[macro_export]
 macro_rules! position {
     [$($color:ident $shape:ident on $square:ident,)*] => {
-        Position::from_iter([
+        $crate::Position::from_iter([
             $(piece!($color $shape on $square)),*
         ].into_iter())
     };