Merge PR #3739 into ci-3739 for CI verification

Author: mshibuya

package.json

@@ -9,6 +9,7 @@
     "src"
   ],
   "main": "src/rails_admin/base.js",
+  "type": "module",
   "scripts": {
     "link": "yarn link && cd spec/dummy_app && yarn link rails_admin",
     "format": "prettier -w ."