Examine source code of GHN Cookie Sync

{
  "manifest_version": 2,
  "name": "GHN Cookie Sync",
  "version": "1.0.9",
  "icons": {
    "32": "assets/icons/favicon-32.png",
    "128": "assets/icons/favicon-128.png",
    "180": "assets/icons/favicon-180.png",
    "192": "assets/icons/favicon-192.png"
  },
  "description": "Sync cookies for local frontend development of GHN SingleWeb",
  "homepage_url": "https://github.com/comehere127/ghn-sync-cookie",
  "short_name": "Cookie Sync",
  "permissions": [
    "cookies",
    "storage",
    "tabs",
    "https://*.ghn.tech/*",
    "http://localhost/*"
  ],
  "content_security_policy": "script-src 'self'; object-src 'self'",
  "author": "TuDHM",
  "browser_specific_settings": {
    "gecko": {
      "id": "{91bede6c-62d4-42d6-a7ac-13a19d9718cc}"
    }
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "GHN Cookie Sync",
    "browser_style": false
  },
  "background": {
    "scripts": [
      "js/serviceworker.bundle.js"
    ]
  }
}