Examine source code of Naurok Helper

{
  "name": "Naurok Helper",
  "version": "1.3.2",
  "manifest_version": 2,
  "icons": {
    "16": "icon/16.png",
    "32": "icon/32.png",
    "48": "icon/48.png",
    "96": "icon/96.png",
    "128": "icon/128.png"
  },
  "permissions": [
    "activeTab",
    "storage",
    "webNavigation",
    "tabs",
    "clipboardWrite"
  ],
  "browser_action": {
    "default_title": "Naurok Helper",
    "default_popup": "src/popup/index.html"
  },
  "content_scripts": [
    {
      "matches": [
        "https://naurok.ua/test/testing/*",
        "https://naurok.com.ua/test/testing/*",
        "https://naurok.com.ua/test/realtime-client/*",
        "https://naurok.ua/test/realtime-client/*"
      ],
      "js": [
        "src/scripts/content_script.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "src/scripts/background.js"
    ],
    "persistent": false
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{df00a1e1-d3e2-4b3b-9335-ea72b0299407}"
    }
  }
}