Feature? lazy dialogs!

[mariusGundersen]

Here is a feature which is already possible today, which is pretty neat:

const MyDialog = createCallable(lazy(() => import('./MyDialog')));

This makes a lazy-loadable dialog which is only loaded when it's needed. Very useful!

This could be simplified a bit, for example if there was a createLazyCallable:

const MyDialog = createLazyCallable(() => import('./MyDialog'));

Not sure if this is necessary to include in the code or just in the documentation.

[desko27]

Docs added! Thanks again to both @mariusGundersen for reporting and @flt3150sk for contributing #64!