Examine source code of Goldtoken Enhancer

{
  "manifest_version": 2,
  "name": "Goldtoken Enhancements",
  "version": "0.6",
  "description": "Enhancements to the Goldtoken.com user interface",
  "content_scripts": [
    {
      "matches": [
        "*://*.goldtoken.com/*"
      ],
      "js": [
        "js/jquery-3.4.1.min.js",
        "js/grabble.js",
        "js/xiphias.js"
      ]
    }
  ]
}