Include ListViewDataSource docs somewhere

[glenjamin]

I guess ideally they should be on the ListView page?

The docblocks in https://github.com/facebook/react-native/blob/master/Libraries/CustomComponents/ListView/ListViewDataSource.js seem fairly complete, I just can't find the info on the docs site.

[pjjanak]

Would be resolve by PR #360

[Crash--]

I think there is a regression here. I can't find the documentation about ListViewDataSource on the ListView page (https://facebook.github.io/react-native/docs/listview.html#datasource)

[satya164]

Same here. ListViewDataSourcedocs will be awesome to have.

[TiagoGouvea]

Needing too.

[mikedizon]

+1

[thunderousNinja]

👍

[wootwoot1234]

+1

[vjeux]

cc @MartinKonicek

[vjeux]

cc @mkonicek