Added a postinstall script to build TS code

Author: artus9033

package.json

@@ -8,7 +8,8 @@
     "build": "tsc",
     "dev": "tsc --watch",
     "test": "echo \"Error: no test specified\" && exit 1",
-    "lint": "eslint ."
+    "lint": "eslint .",
+    "postinstall": "npm run build"
   },
   "repository": {
     "type": "git",