build: add exports entry

Author: wewoor

package.json

@@ -9,6 +9,9 @@
   "main": "lib/index.js",
   "module": "lib/index.js",
   "types": "lib/index.d.ts",
+  "exports": {
+    "./": "lib/"
+  },
   "scripts": {
     "storybook": "start-storybook -p 9001 -c .storybook",
     "build-storybook": "build-storybook -c .storybook",