Examine source code of Elegant Undo Close Tab

{
  "name": "Elegant Undo Close Tab",
  "description": "__MSG_extensionDesc__",
  "version": "1.0.3.0",
  "version_name": "1.0.3",
  "manifest_version": 3,
  "action": {
    "default_popup": "src/ui/action-popup/index.html"
  },
  "background": {
    "scripts": [
      "service-worker-loader.js"
    ],
    "type": "module"
  },
  "devtools_page": "src/devtools/index.html",
  "options_page": "src/ui/options-page/index.html",
  "offline_enabled": true,
  "host_permissions": [
    "<all_urls>"
  ],
  "default_locale": "en",
  "permissions": [
    "storage",
    "tabs"
  ],
  "web_accessible_resources": [
    {
      "matches": [
        "<all_urls>"
      ],
      "resources": [
        "src/ui/setup/index.html",
        "src/ui/content-script-iframe/index.html",
        "src/ui/devtools-panel/index.html"
      ]
    }
  ],
  "icons": {
    "16": "src/assets/logo.png",
    "24": "src/assets/logo.png",
    "32": "src/assets/logo.png",
    "128": "src/assets/logo.png"
  },
  "author": "goodzhuwang@gmail.com",
  "browser_specific_settings": {
    "gecko": {
      "id": "elegent-undo-close-tab@dingdangbox.com"
    }
  }
}