Examine source code of Shorten Joli Url

{
  "manifest_version": 2,
  "name": "Shorten Joli Url",
  "version": "1.0",
  "description": "Shorten URLs on the fly with JoliURL.com.",
  "icons": {
    "128": "icons/logo.svg"
  },
  "permissions": [
    "activeTab",
    "https://joliurl.com/"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "32": "icons/logo.svg"
    }
  },
  "default_locale": "en",
  "browser_specific_settings": {
    "gecko": {
      "id": "{2cb2f379-61cd-4942-b3e3-ba6a4add774f}"
    }
  }
}