Improve fullscreen documenation (#364)

README.md

@@ -88,6 +88,9 @@ Under `.addPackage(new MainReactPackage())`:
 // on a single screen if you like.
 
 <Video source={{uri: "background"}}   // Can be a URL or a local file.
+       ref={(ref) => {
+         this.player = ref
+       }}                             // Store reference
        rate={1.0}                     // 0 is paused, 1 is normal.
        volume={1.0}                   // 0 is muted, 1 is normal.
        muted={false}                  // Mutes the audio entirely.
@@ -104,6 +107,12 @@ Under `.addPackage(new MainReactPackage())`:
        onError={this.videoError}      // Callback when video cannot be loaded
        style={styles.backgroundVideo} />
 
+// Later to trigger fullscreen
+this.player.presentFullscreenPlayer()
+
+// To set video position in seconds (seek)
+this.player.seek(0)
+
 // Later on in your styles..
 var styles = StyleSheet.create({
   backgroundVideo: {
@@ -171,6 +180,10 @@ To enable audio to play in background on iOS the audio session needs to be set t
 
 Seeks the video to the specified time (in seconds). Access using a ref to the component
 
+`presentFullscreenPlayer()`
+
+Toggles a fullscreen player. Access using a ref to the component.
+
 ## Examples
 
 - See an [Example integration][1] in `react-native-login` *note that this example uses an older version of this library, before we used `export default` -- if you use `require` you will need to do `require('react-native-video').default` as per instructions above.*