migrate JS example to ESM

Author: antonok-edm

README.md

@@ -29,7 +29,7 @@ It may be a good fit for yours, too!
 
 See [docs.rs](https://docs.rs/adblock) for detailed API documentation.
 
-Also check the [Rust example](./examples/example.rs) or the [NodeJS example](./js/example.js).
+Also check the [Rust example](./examples/example.rs) or the [NodeJS example](./js/example.mjs).
 
 ### Optional features
 

js/example.js renamed to js/example.mjs

@@ -1,5 +1,5 @@
-const adblockRust = require('adblock-rs');
-const fs = require('fs');
+import adblockRust from 'adblock-rs';
+import fs from 'node:fs';
 const dataPath = '../data/'
 
 const debugInfo = true;