Add stacked belts to station

factorio-blueprint-generator/src/multistation.rs

@@ -15,6 +15,7 @@ pub struct StationSpec {
     pub beltspeed: Beltspeed,
     pub lanes: usize,
     pub belttype: Belttype,
+    pub stacked: bool,
 }
 
 fn calculate_station_height(
@@ -268,6 +269,7 @@ pub fn multistation(
             station.lanes,
             station.beltspeed,
             station.belttype,
+            station.stacked,
         );
         let output_height = -b.bounding_box().min().y;