Examine source code of rate-a-website

{
  "name": "rate-a-website",
  "version": "1.0",
  "manifest_version": 2,
  "description": "Rate a website",
  "icons": {
    "16": "assets/icons/completed-task_16.png",
    "48": "assets/icons/completed-task_48.png",
    "128": "assets/icons/completed-task_128.png"
  },
  "browser_action": {
    "default_icon": {
      "16": "assets/icons/completed-task_16.png",
      "48": "assets/icons/completed-task_48.png",
      "128": "assets/icons/completed-task_128.png"
    },
    "default_title": "rate-a-website",
    "default_popup": "/popup/index.html"
  },
  "permissions": [
    "tabs",
    "activeTab"
  ]
}