Examine source code of bookmark randomizer

{
  "manifest_version": 2,
  "name": "bookmark randomizer",
  "default_locale": "en",
  "version": "0.0.2resigned1",
  "description": "A small utility to open a page from your bookmarks randomly! ShortCut: Alt+Shift+R",
  "icons": {
    "128": "img/logo.png"
  },
  "applications": {
    "gecko": {
      "id": "guoliang1222@gmail.com",
      "strict_min_version": "44.0"
    }
  },
  "permissions": [
    "bookmarks",
    "tabs",
    "storage"
  ],
  "background": {
    "scripts": [
      "background/background.js"
    ]
  },
  "options_ui": {
    "page": "options/options.html"
  },
  "browser_action": {
    "default_title": "bookmark randomizer",
    "default_icon": "img/logo.png"
  },
  "commands": {
    "randomize": {
      "suggested_key": {
        "default": "Alt+Shift+R"
      },
      "description": "randomize a page and open"
    }
  }
}