"index": {
  "name": "category-name",
  "subtitle": "Category's name",
  "tags": ["category's tags"], // "used in the filters: 'framework', 'language', 'conceptual', 'frontend', 'mobile'"
  "about": "Category's description",
  "site": "url of the official category site",
  "image": "category-image.jpg", // Category image is required
  "books": [
    {
      "title": "Book title",
      "description": "Book description",
      "author": "Author name or Publisher name",
      "pages": 100, // Number of pages
      "year": 2014, // Publish year
      "lang": "EN", // book language. Ex.: EN, PT-BR, ES
      "url": "book's url to download",
      "added_at": "20161112" // Current date you added this book in format YYYYMMDD
    }
  ]
},

{
  "index": {
    "name": "nodejs",
    "subtitle": "Node.js",
    "tags": ["language", "framework"],
    "about": "Node.js is a platform built on Chrome's JavaScript runtime for easily building fast, scalable network applications. Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient, perfect for data-intensive real-time applications that run across distributed devices.",
    "site": "http://nodejs.org",
    "image": "nodejs.png",
    "books": [
      {
        "title": "Node.js Succinctly",
        "description": "Learn the basics of Node.js: non-blocking I/O, the event loop, modules, and the Node.js runtime environment. From there, dive into building practical solutions that interact with filesystems and streams, access databases, handle web server message queuing, and more.",
        "author": "Emanuele DelBono",
        "pages": 76,
        "year": 2016,
        "lang": "EN",
        "added_at": "20161112",
        "url": "https://www.syncfusion.com/resources/techportal/details/ebooks/nodejs"
      }
    ]
  }
}