TestGatsbySanity/studio/plugins/dashboard-widget-structure-menu/sanity.json

{
  "paths": {
    "source": "./src",
    "compiled": "./lib"
  },
  "parts": [
    {
      "name": "part:@sanity/dashboard/widget/create",
      "implements": "part:@sanity/dashboard/widget",
      "path": "widget.js"
    }
  ]
}