Add exports field to react-refresh's package.json (#23087)

* Add exports field to react-refresh's package.json

* Update package.json

* Add runtime to exports

Author: otakustay

packages/react-refresh/package.json

@@ -18,6 +18,12 @@
     "umd/"
   ],
   "main": "runtime.js",
+  "exports": {
+    ".": "./runtime.js",
+    "./runtime": "./runtime.js",
+    "./babel": "./babel.js",
+    "./package.json": "./package.json"
+  },
   "repository": {
     "type": "git",
     "url": "https://github.com/facebook/react.git",
@@ -31,4 +37,4 @@
     "react-dom-16-8": "npm:react-dom@16.8.0",
     "scheduler-0-13": "npm:scheduler@0.13.0"
   }
-}
+}