Examine source code of WebSaver Multi Format

{
  "manifest_version": 2,
  "name": "WebSaver Multi Format Page Saver",
  "version": "1.0",
  "description": "Save any webpage instantly as PDF, HTML, or TXT with one click.",
  "icons": {
    "48": "./icons/icon48.png",
    "128": "./icons/icon128.png"
  },
  "browser_action": {
    "default_popup": "index.html",
    "default_icon": "./icons/icon128.png"
  },
  "permissions": [
    "tabs",
    "downloads",
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{47c36e20-96e0-43d8-a875-deed2a987265}"
    }
  }
}