react.dev/beta/src/sidebarReference.json

{
  "title": "API Reference",
  "heading": true,
  "path": "/reference",
  "routes": [
    {
      "heading": true,
      "path": "",
      "routes": [
        {
          "title": "React APIs",
          "path": "/reference",
          "routes": [
            {
              "title": "useState()",
              "path": "/reference/usestate"
            }
          ]
        },
        {
          "title": "ReactDOM APIs",
          "path": "/reference/reactdom",
          "routes": [
            {
              "title": "render()",
              "path": "/reference/render"
            }
          ]
        }
      ]
    }
  ]
}