fix: Export ESM module

Author: Trygve Lie

package.json

@@ -18,6 +18,11 @@
   },
   "license": "Apache-2.0",
   "author": "Justin Poehnelt",
+  "type": "module",
+  "exports": {
+    "import": "./dist/index.esm.js",
+    "require": "./dist/index.umd.js"
+  },
   "main": "dist/index.umd.js",
   "unpkg": "dist/index.min.js",
   "module": "dist/index.esm.js",