Remove unnecessary default.

src/map.rs

@@ -78,19 +78,11 @@ impl ITileType for Tile {
     }
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, Default)]
 pub struct MapConfig {
     pub start_revealed: bool,
 }
 
-impl Default for MapConfig {
-    fn default() -> Self {
-        Self {
-            start_revealed: false,
-        }
-    }
-}
-
 #[derive(Bundle, Default)]
 pub struct PortalBundle {
     pub portal: Portal,