Merge pull request #582 from aexmachina/patch-1

Create README for example

Examples/simple-fcm-client/README.md

+# simple-fcm-client
+
+## iOS
+
+### Installation
+
+- `yarn install`
+- Overwrite `ios/GoogleService-info.plist` with your file
+- Change the _Bundle Identifier_ in Xcode project settings
+- Select your _Team_ for both targets (`SimpleFcmClient` and `SimpleFcmClientTests`)
+
+## Android
+
+TBA - PRs welcome!