Section support

[malashkevich]

Hello @talkol! Thanks for this tutorial (I mean post on medium) and this repository. Your solution don't include such thing as sections headers. So I would like to ask your advice on implementing this feature, if you don't mind. I already was able to pass sections to native and implement native section headers. So the last step - use JSX component with your binding. I think it's not possible to cache section headers in same way like table cells, so may be you can advice me a way to implement this? Thanks in advance.