Examine source code of Autosubmit

{
  "name": "Autosubmit",
  "version": "1.3",
  "icons": {
    "128": "icon_128.png"
  },
  "manifest_version": 2,
  "content_scripts": [
    {
      "matches": [
        "https://docs.google.com/forms/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html",
    "default_title": "Autosubmit"
  }
}