Examine source code of Print Edit WE AD

{
  "manifest_version": 2,
  "name": "Print Edit WE",
  "version": "1.2",
  "description": "Edit web pages before printing them.",
  "permissions": [
    "activeTab",
    "storage"
  ],
  "browser_action": {
    "default_icon": "icons/logo_64.png",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "options_page": "options.html",
  "browser_specific_settings": {
    "gecko": {
      "id": "{00e343fc-02a4-47ad-9a49-d10bf5d464e6}"
    }
  }
}