Examine source code of Goodreads Wizard

{
  "manifest_version": 3,
  "name": "Goodreads Wizard",
  "description": "Let's tune Goodreads ",
  "version": "1.4",
  "permissions": [
    "storage"
  ],
  "action": {
    "default_icon": "assets/img/icon.png",
    "default_popup": "popup.html"
  },
  "icons": {
    "128": "assets/img/icon_128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "s@vgnx.fr"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.goodreads.com/*"
      ],
      "css": [
        "assets/css/enhancer.css"
      ],
      "js": [
        "assets/js/enhancer.js"
      ],
      "run_at": "document_start"
    }
  ]
}