feat: example app

[helenaford]

Skeleton Example App

• Application Code is located at example/src and example/App.tsx
• Can recreate example app (./example) by running script ./refresh-example.sh
• The script will copy the application code in a temporary directory (TEMP), rebuild the boilerplate react-native app, and move the code back.

Script to generate demo app is originally from @mikehardy's rnfbdemo

How to run:

• ./refresh-example.sh (optional as there will always be a version of the app built template/demo)
• cd ./example
• yarn install
• cd ./ios && pod install
• yarn react-native run-ios

Outstanding (to be added later):

• Extend the notification examples to demonstrate more of notifee's functionality
• Add FCM (or show in playground app)
• Add detox testing
• Add jest testing