Add declaration file for TypeScript (#40)

Author: snaptopixel

index.d.ts

@@ -0,0 +1,8 @@
+import {Store} from 'vuex';
+import VueRouter = require('vue-router');
+
+interface SyncOptions {
+  moduleName: string;
+}
+
+export declare function sync(store: Store<any>, router: VueRouter, options?: SyncOptions);