Conditionally add HTML attributes (e.g. `required`, `disabled`)

[DannyJJK]

The Feature Request

There are some HTML attributes that don't have a way to specifiy if the attribute is enabled or disabled, and there are some attributes that don't allow a blank value (e.g. aria-current). Using the disabled attribute as an example, if a button is enabled, it would be:

<button>Test</button>

If a button is disabled, it would be:

<button disabled>Test</button>

Unless I have missed something in the documentation, the only way I can see to do this in SuperHTML is to use <ctx :if="condition"> and write the whole button HTML twice, one for if it's enabled and one for if it's disabled.