Feature: Implement an announcement notification system

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The announcement:

• should be added and edited only by selected people
• should raise an app notification when an announcement is added, only once

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Find information in these links:

• https://github.com/techwithsam/flutter-push-notification-without-firebase/blob/master/lib/main.dart
• https://firebase.google.com/docs/cloud-messaging?hl=de

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https://medium.com/@saminchandeepa/a-comprehensive-guide-to-implement-notifications-in-flutter-32155df65c40

https://medium.com/@harsh.ripenapps/a-guide-to-implementation-of-push-notification-in-flutter-apps-9b7647359633