useResource "submit" method is mis-typed

[pschwyter]

The submit method seems to be mis-typed as being synchronous. However, it's an async function!

Code:
https://github.com/badgateway/react-ketting/blob/main/src/hooks/use-resource.ts#L86

const submit = async () => {
    if (!resourceState || !resource) {
      throw new Error('Too early to call submit()');
    }
    await resource.put(resourceState);
  };

Type:
https://github.com/badgateway/react-ketting/blob/main/src/hooks/use-resource.ts#L21

// Send the state to the server via a PUT or POST request.
  submit: (state?: ResourceState<T>) => void;

[evert]

Originally by design because I wasn't sure what we were going to do with this method, but at this point I think it's fine to change to Promise<void>