{
  "metadata": {
    "title": "Main Menu"
  },

  "links": [
    { "rel": "self", "href": "index.json", "type": "application/opds+json" }
  ],
  "navigation": [
    {
      "href": "grade1/grade1.json",
      "title": "Grade 1",
      "type": "application/opds+json",
      "alt": [
        {
          "href": "grade1/lesson001/cover.png",
          "rel": "icon",
          "type": "image/png",
          "title": "Book"
        }
      ]
    }
  ]
}