Examine source code of WhatRuns Detector V2

{
  "manifest_version": 2,
  "name": "WhatRuns Detector V2",
  "version": "1.3",
  "description": "Detect what runs behind any website - frameworks, analytics tools, fonts, and more.",
  "icons": {
    "32": "icons/logo_32.png",
    "64": "icons/logo_64.png",
    "128": "icons/logo_128.png"
  },
  "permissions": [
    "tabs",
    "activeTab",
    "<all_urls>"
  ],
  "browser_action": {
    "default_icon": "icons/logo_64.png",
    "default_popup": "popup.html",
    "default_title": "WhatRuns Detector"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "web_accessible_resources": [
    "style.css"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{e78d7d24-6b61-485e-b272-7e5f1ef43a0d}"
    }
  }
}