Merge pull request #1406 from OneSignal/add_migration_advisory_to_readme

Add migration advisory to readme and migration guide

Author: nan-li

MIGRATION_GUIDE.md

@@ -2,6 +2,21 @@
 
 ![OneSignal Omni Channel Banner](https://user-images.githubusercontent.com/11739227/208625336-d28c8d01-a7cf-4f8e-9643-ac8d1948e9ae.png)
 
+---
+
+#### ⚠️ Migration Advisory for current OneSignal customers
+
+Our new [user-centric APIs and v5.x.x SDKs](https://onesignal.com/blog/unify-your-users-across-channels-and-devices/) offer an improved user and data management experience. However, they may not be at 1:1 feature parity with our previous versions yet.
+
+If you are migrating an existing app, we suggest using iOS Phased Rollout capabilities to ensure that there are no unexpected issues or edge cases. Here is the documentation:
+
+- [iOS Phased Rollout](https://developer.apple.com/help/app-store-connect/update-your-app/release-a-version-update-in-phases/)
+
+
+If you run into any challenges or have concerns, please contact our support team at [email protected]
+
+---
+
 # Intro
 
 In this release, we are making a significant shift from a device-centered model to a user-centered model. A user-centered model allows for more powerful omni-channel integrations within the OneSignal platform.

README.md

@@ -7,6 +7,19 @@
 
 ---
 
+#### ⚠️ Migration Advisory for current OneSignal customers
+
+Our new [user-centric APIs and v5.x.x SDKs](https://onesignal.com/blog/unify-your-users-across-channels-and-devices/) offer an improved user and data management experience. However, they may not be at 1:1 feature parity with our previous versions yet.
+
+If you are migrating an existing app, we suggest using iOS Phased Rollout capabilities to ensure that there are no unexpected issues or edge cases. Here is the documentation:
+
+- [iOS Phased Rollout](https://developer.apple.com/help/app-store-connect/update-your-app/release-a-version-update-in-phases/)
+
+
+If you run into any challenges or have concerns, please contact our support team at [email protected]
+
+---
+
 [OneSignal](https://www.onesignal.com) is a free email, sms, push notification, and in-app message service for mobile apps. This plugin makes it easy to integrate your native iOS app with OneSignal.
 
 <p align="center"><img src="https://app.onesignal.com/images/ios_10_notification_image.gif" width="400" alt="iOS Notification"></p>