Start to rework the graphics for the wires layer, make wires cooler than belts

src/js/core/config.js

@@ -51,9 +51,15 @@ export const globalConfig = {
     // Belt speeds
     // NOTICE: Update webpack.production.config too!
     beltSpeedItemsPerSecond: 2,
-    itemSpacingOnBelts: 0.63,
     minerSpeedItemsPerSecond: 0, // COMPUTED
 
+    beltItemSpacingByLayer: {
+        regular: 0.63,
+        wires: 0.33,
+    },
+
+    wiresSpeedItemsPerSecond: 6,
+
     undergroundBeltMaxTilesByTier: [5, 8],
 
     buildingSpeeds: {