Now that we know how to use partials, one might ask how to render a menu in a recursive way. For this, we only need another tag for explicitely manipulating the scope.

* sharp (#) renders its second block, in the scope of the value evaluated in first block

For the example above, our menu rendering is initiated as follows:
    <ul>
  <li>About</li>
  <li>Products</li>
  <ul>
  <li>WLang</li>
  <li>Alf</li>
  <li>Viiite</li>
</ul>
</ul>

Note that it is important to keep empty menus in the source data to avoid infinite recursions due the parent scope that already binds a value under `menu`.