feat: async generator functions / async components

Hey, thanks for your work on this lib.

Crank.js allows components to be defined as [async generator functions](https://crank.js.org/guides/async-components). For example:
```js
async function IPAddress () {
const res = await fetch("https://api.ipify.org");
const address = await res.text();
return

await renderer.render(, document.body);
console.log(document.body.innerHTML); //

Can Hacky support it too? It seems it would be mostly a matter of adding `await` in some parts of the code.