fix typescript types issue with esm (#780)

package.json

@@ -5,6 +5,7 @@
   "types": "./index.d.ts",
   "exports": {
     "import": "./ESM_wrapper.mjs",
-    "require": "./uws.js"
+    "require": "./uws.js",
+    "types": "./index.d.ts"
   }
 }