Examine source code of Webpage Screenshot

{
  "manifest_version": 2,
  "name": "Webpage Screenshot",
  "version": "1.0",
  "description": "Capture and save screenshots of any webpage with a single click.",
  "icons": {
    "48": "icon.png"
  },
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html",
    "default_title": "Capture Screenshot"
  },
  "permissions": [
    "activeTab",
    "downloads"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{5071d257-65d6-465b-be72-4031fb8fb262}"
    }
  }
}