Avoid top lvl await in page init

[hsn10]

More compatible init code because older browsers do not have top level await. Solves problems with mobile users which can't update. Seems like this JS feature landed in 2021.

https://caniuse.com/mdn-javascript_operators_await_top_level

<script type=module>
    import init from './pkg/counter.js';
    init().then(() => {
        console.log('Module initialized successfully');
    }).catch(console.error);
</script>