Update package.json:

* rename index.module.js to index.mjs

Author: Palbahngmiyine

package.json

@@ -28,7 +28,7 @@
   "source": "src/solapi.ts",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",
-  "module": "dist/index.module.js",
+  "module": "dist/index.mjs",
   "files": [
     "/dist"
   ],