Examine source code of Temporary Bookmarks

{
  "name": "Temporary Bookmarks",
  "version": "1.3",
  "description": "Automatically delete expired bookmarks in a folder.",
  "icons": {
    "16": "icons/icon-16.png",
    "19": "icons/icon-19.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "permissions": [
    "<all_urls>",
    "bookmarks",
    "tabs",
    "storage"
  ],
  "options_ui": {
    "chrome_style": true,
    "open_in_tab": true,
    "page": "index.html"
  },
  "browser_action": {
    "default_icon": "icons/icon-19.png",
    "default_title": "temporary bookmarks"
  },
  "background": {
    "scripts": [
      "js/bookmarks.js",
      "js/background.js"
    ]
  },
  "commands": {
    "add-bookmark": {
      "description": "Add bookmarks to the folder"
    }
  },
  "manifest_version": 2,
  "browser_specific_settings": {
    "gecko": {
      "id": "{8544cc0d-20ed-4aa9-952c-2f330c682734}"
    }
  }
}