Add example plugin

Summary: Added example plugin for iOS, similar to android

Reviewed By: jknoxville

Differential Revision: D10492429

fbshipit-source-id: d639edc7a47ab240bb172516c2f38b8e2a9f285c

iOS/Plugins/FlipperKitExamplePlugin/FlipperKitExamplePlugin/FlipperKitExamplePlugin.h

@@ -0,0 +1,18 @@
+/*
+ *  Copyright (c) 2018-present, Facebook, Inc.
+ *
+ *  This source code is licensed under the MIT license found in the LICENSE
+ *  file in the root directory of this source tree.
+ *
+ */
+#import <Foundation/Foundation.h>
+#import <FlipperKit/FlipperPlugin.h>
+
+@interface FlipperKitExamplePlugin : NSObject<FlipperPlugin>
+
+- (instancetype)init NS_UNAVAILABLE;
+- (void)sendMessage:(NSString *)msg;
+- (void)triggerNotification;
++ (instancetype) sharedInstance;
+
+@end