Christine Abernathy 82b99a1ca3 Update MapView doc ...

Summary:
Reference: #8203

Changes made:

- Added a MapView example to the intro section
- Added more details to prop explanations
- Added more info to an exported type, even if it's not used anywhere I can see
- Removed mention of ios platform in props. Left an android one in there as I didn't want to touch code.

**Test plan (required)**

Ran the website locally and checked: http://localhost:8079/react-native/docs/mapview.html

![component_mapview_2](https://cloud.githubusercontent.com/assets/691109/16329753/43419508-3999-11e6-9310-11c53ca8c04b.png)
Closes https://github.com/facebook/react-native/pull/8389

Differential Revision: D3481609

Pulled By: JoelMarcey

fbshipit-source-id: 71e35ce49193dc09d40546ff16bc48559135d63f

2016-06-24 07:00:45 -07:00

..

MapView.js

Update MapView doc

2016-06-24 07:00:45 -07:00