Support for generic cells and headers

[ka05]

This allow you to use multiple different cell types within a sectioned recycler view.

[ka05]

@jaychang0917 Just curious if you have had the opportunity to look this over?

[ka05]

@jaychang0917 Is anyone still maintaining this repo?

[devsparkles]

you can do a fork.. in the worst case scenario. I think he is not responding because he is under a lot of work