react-native example app port (#223)

* add readme

* react-native example app

* update readme

* add ios-cli dep

* revert package.json change

* update readme

* update readme

* don't auto launch metro

* add react native scripts

* nohoist @react-native-community/**

* update readme

* undo wrong README change

* remove react-native root dep

* copyright headers

* semi-style

* add default gitignore

* finish linting

* remove test for now

* fix typescript errors

* fix linting

* update scripts

* update deps and version

* update readme

* remove accidental dep

* update readme

* bump deps

* update yarn.lock

* actually update yarn.lock

* fix yarn.lock conflicts by updating exampleReactNative deps

packages/exampleReactNative/ios/exampleReactNative/main.m

@@ -0,0 +1,16 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#import <UIKit/UIKit.h>
+
+#import "AppDelegate.h"
+
+int main(int argc, char * argv[]) {
+  @autoreleasepool {
+    return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class]));
+  }
+}