Various updates for React Native Windows
**Docs**
* Fixed windows installation in readme
* Added local dev setup instructions
**Build**
* Added VS solutions for RNW 0.61, 0.62, and 0.63+
* Added clang-formatting definition
**Features**
* Fixed autolinking for RNW 0.63+
* Added support for `rate` property
**Examples**
* Upgraded examples/basic to RN 0.61 and replaced broken windows app
* initial support for WPF
* update readme with WPF specific instructions
* remove autogenerated .gitattributes file
* reference RNW NPM package instead of hard-coded local reference
This PR adds react-native-windows support to react-native-video. The Video component is implemented with a XAML MediaPlayerElement. Most of the features implemented by Android (and some additional ones) are implemented by Windows.
Known issues and missing features include:
* onReadyForDisplay event
* local URI convention (e.g., "broadchurch" in examples changed to require("./broadchurch.mp4")
* `playableDuration` in `onVideoProgress` event is always 0.0
* `playInBackground` is not yet supported
* Volume settings are applied, but the UWP control does not handle it properly