Support dataset and attributes keys
Support dataset and attributes keys

In the virtual-dom hyperscript implementation, the properties `dataset` and `attributes` are nested properties that get translated onto the resulting node: https://github.com/Matt-Esch/virtual-dom/blob/903d884a8e4f05f303ec6f2b920a3b5237cf8b92/test/nested-properties.js#L45-L74

This does the same behaviour, allowing this project to support the use case of someone converting a project from virtual-dom to react-dom i.e. my use case :)

Cheers,
-glen.
mlmorg/react-hyperscript