Try to fix Snap: Added Typescript.

package.json

@@ -80,6 +80,7 @@
     "qs": "^6.9.6",
     "source-map-resolve": "^0.6.0",
     "source-map-support": "^0.5.19",
+    "typescript": "^4.1.3",
     "xss": "^1.0.8"
   }
 }