[Docs question] useForm

### Are you submitting a **bug report** or a **feature request**?

Question about the documentation

### What is the current behavior?

The doc states:
```
The useForm hook plucks the FormApi out of the React context for you. It will throw an exception if you try to use it outside of a component.
```

Which confused me at first, because what would be the use of `useForm` if you still needed `Form`?

Then I found this Codesandbox: https://codesandbox.io/s/zqkj5706y3, which doesn't use `Form`.

I think the doc should be updated, and I would gladly do it but maybe I'm mistaken, or maybe there was some intent behind the original description?

Thanks in advance for looking into it!