refactor: move road compiler core into package

src/index.js

@@ -0,0 +1,13 @@
+"use strict";
+
+module.exports = {
+  laneGeometry: require("./geometry/lane-geometry"),
+  gaodeReference: require("./reference/gaode"),
+  turnLaneArrows: require("./compile/turn-lane-arrows"),
+  complexJunction: require("./compile/complex-junction"),
+  osm: require("./osm"),
+  trafficSignals: require("./traffic-signals"),
+  nativeTrafficSignals: require("./native-traffic-signals"),
+  nativeRoad: require("./compile/native-road"),
+  compiler: require("./compile/compiler"),
+};