Example of getPhotos Method

Summary:
Example for loading Media using CameraRoll getPhotos method

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The cameraRoll API doesn't have a proper example of how to use the methods. So, I decided to provide a basic example with a use case.

(Write your test plan here. If you changed any code, please provide us with clear instructions on how you verified your changes work. Bonus points for screenshots and videos!)
Closes https://github.com/facebook/react-native/pull/15647

Differential Revision: D5748965

Pulled By: hramos

fbshipit-source-id: df8ad50d597dcc745a7f6abcc52839695ffe452c

Libraries/CameraRoll/CameraRoll.js

@@ -217,6 +217,43 @@ class CameraRoll {
    *      - `has_next_page`: {boolean}
    *      - `start_cursor`: {boolean}
    *      - `end_cursor`: {boolean}
+   *
+   * Loading images:
+   * ```
+   * _handleButtonPress = () => {
+   *    CameraRoll.getPhotos({
+   *        first: 20,
+   *        assetType: 'All',
+   *      })
+   *      .then(r => {
+   *        this.setState({ photos: r.edges });
+   *      })
+   *      .catch((err) => {
+   *         //Error Loading Images
+   *      });
+   *    };
+   * render() {
+   *  return (
+   *    <View>
+   *      <Button title="Load Images" onPress={this._handleButtonPress} />
+   *      <ScrollView>
+   *        {this.state.photos.map((p, i) => {
+   *        return (
+   *          <Image
+   *            key={i}
+   *            style={{
+   *              width: 300,
+   *              height: 100,
+   *            }}
+   *            source={{ uri: p.node.image.uri }}
+   *          />
+   *        );
+   *      })}
+   *      </ScrollView>
+   *    </View>
+   *  );
+   * }
+   * ```
    */
   static getPhotos(params) {
     if (__DEV__) {