Examine source code of Site Downloader

{
  "manifest_version": 2,
  "name": "Site Downloader",
  "version": "0.1",
  "description": "Download websites for offline viewing",
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "permissions": [
    "activeTab",
    "tabs",
    "storage",
    "downloads",
    "<all_urls>",
    "downloads.open"
  ],
  "browser_action": {
    "default_icon": {
      "48": "icons/icon-48.png",
      "96": "icons/icon-96.png"
    },
    "default_title": "Website Downloader",
    "default_popup": "popup/popup.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "type": "module"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content_scripts/downloader.js"
      ]
    }
  ],
  "content_security_policy": "script-src 'self'; object-src 'self';",
  "browser_specific_settings": {
    "gecko": {
      "id": "{5dde9448-5e27-4bc1-bbb6-a66f62887124}"
    }
  }
}