book.json

{
  "gitbook": ">=3.2.2",
  "title": "React Image Gallery",
  "root": "./docs",
  "plugins": [ "theme-api"],
  "pluginsConfig": {
    "theme-api": {
      "languages": [
        {
          "lang": "js",
          "name": "JavaScript",
          "default": true

        }
      ]
    },
    "codepen":{
      "height": 1000,
      "theme": "light",
      "defaultTab": "js"
    }
  }
}