Improve `.hpx` files 🔥
```vue
<script lang="nim">
  var age = 10
</script>
<div h-if="age < 20">
  You're young!
</div>
<div h-elif="age < 30">
  You're already young!
</div>
<div h-else>
  You're old!
</div>
<div h-for="i in [1, 2, 3, 4]">
  {i}
</div>
```