Add typescript types for node js as dev dependency

Author: Simon Planinschek

package.json

@@ -39,6 +39,7 @@
   },
   "homepage": "https://github.com/aboutbits/internationalization#readme",
   "devDependencies": {
+    "@types/node": "^14.11.5",
     "@types/jest": "^26.0.9",
     "@typescript-eslint/eslint-plugin": "^3.8.0",
     "@typescript-eslint/parser": "^3.8.0",