Examine source code of Kobo Add Series

{
  "name": "Kobo Add Series",
  "version": "0.1",
  "description": "A helpful button to add the whole series to your cart.",
  "content_scripts": [
    {
      "matches": [
        "https://www.kobo.com/*"
      ],
      "js": [
        "koboAddAll.js"
      ],
      "css": [
        "style.css"
      ]
    }
  ],
  "manifest_version": 2
}