Implement initial Pawn setup

rs/src/main.rs

@@ -1,3 +1,4 @@
+#[derive(Clone)]
 enum Color {
     Black,
     White,
@@ -128,10 +129,31 @@ impl GridAxis for Column {
     }
 }
 
+#[derive(Clone)]
 enum PieceType {
     Pawn,
 }
 
+impl PieceType {
+    fn initial_setup(&self) -> Vec<Piece> {
+        match &self {
+            PieceType::Pawn => [Color::Black, Color::White]
+                .iter()
+                .flat_map(|color| {
+                    Column::ALL_VALUES.iter().map(|&column| Piece {
+                        piece_type: self.clone(),
+                        position: Position {
+                            row: color.get_pawn_row(),
+                            column,
+                        },
+                        color: color.clone(),
+                    })
+                })
+                .collect(),
+        }
+    }
+}
+
 struct Piece {
     position: Position,
     color: Color,