Summary:
Simple API takes structured `sections` prop instead of `data` array. `sections` is an array of
`Section` objects, each of which has a `key` and an `itemData` array which is analogous to a
`FlatList` `data` prop, plus optional props like `ItemComponent` that can be overridden on a
per-section level, allowing heterogeneous section item rendering via clean composition.
Flattens the sections data and renders with VirtualizedList under the hood. Doesn't support
sticky headers yet.
Reviewed By: yungsters
Differential Revision: D4519354
fbshipit-source-id: 58de959dadb6f55f681245ecd99a5dc356a48f36
Spencer Ahrens