added weback and webpack-cli as dev dependencies

package.json

@@ -3,5 +3,9 @@
   "version": "10.2.1",
   "description": "Web interface for Jellyfin",
   "repository": "https://github.com/jellyfin/jellyfin-web",
-  "license": "GPL-2"
+  "license": "GPL-2",
+  "devDependencies": {
+    "webpack": "^4.29.5",
+    "webpack-cli": "^3.2.3"
+  }
 }