Examine source code of Link Extractor

{
  "manifest_version": 2,
  "name": "Link Extractor",
  "version": "1.0",
  "description": "Extracts all links from the page, including redirect links, and shows unique domains.",
  "permissions": [
    "tabs",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Extract Links",
    "default_icon": {
      "64": "icon64.png",
      "128": "icon128.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "web_accessible_resources": [
    "extractor.html"
  ],
  "icons": {
    "64": "icon64.png",
    "128": "icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{774c6dae-65ca-4c7c-8f94-55dae0671056}",
      "strict_min_version": "104.0"
    }
  }
}