Add deprecation notice and migration guide (#385)

README.md

@@ -1,3 +1,38 @@
+# :warning: Deprecation Notice :warning:
+
+## Use [`@sentry/react-native`](https://github.com/getsentry/sentry-react-native) directly 
+
+As of 18 Jan 2024, the release of [Expo SDK 50](https://expo.dev/changelog/2024/01-18-sdk-50), **sentry-expo** is deprecated and will no longer receive updates.
+
+### Migrate to [`@sentry/react-native`](https://github.com/getsentry/sentry-react-native)
+
+For guidance on migrating, please see our migration guides:
+
+- [Migrating from sentry-expo to @sentry/react-native](https://github.com/expo/fyi/blob/main/sentry-expo-migration.md) by Expo
+- [Migrate from sentry-expo](https://docs.sentry.io/platforms/react-native/migration/sentry-expo/) by Sentry
+
+### Install `@sentry/react-native` for the first time
+
+For first-time installation guidance, please follow the installation guides:
+
+- [A guide on installing and configuring Sentry for crash reporting](https://docs.expo.dev/guides/using-sentry/) by Expo
+- [Set up Sentry React Native SDK in your Expo project](https://docs.expo.dev/guides/using-sentry/) by Sentry
+
+### Questions & Support
+
+While official support is no longer provided, you might find help from the community in [Expo Discord](https://discord.com/invite/expo) and [Sentry Discord](https://discord.com/invite/sentry). Additionally, the [documentation for SDK 49 and below](https://docs.expo.dev/guides/using-sentry/) will remain available as a reference.
+
+Thank you for your understanding and support. If you have any questions, please open an issue in [`@sentry/react-native`](https://github.com/getsentry/sentry-react-native) repository, and we'll do our best to provide guidance.
+
+### What the deprecation means for you
+
+- `sentry-expo` keeps working as is in SDK 49 and older.
+- **No New Features:** The library will not receive new features.
+- **No Bug Fixes:** Existing versions will not receive bug fixes.
+- **Security Vulnerabilities:** We will not address new security vulnerabilities.
+
+
+# Original `README.md` below
 
 [![runs with expo](https://img.shields.io/badge/Runs%20with%20Expo-4630EB.svg?style=flat-square&logo=EXPO&labelColor=f3f3f3&logoColor=000)](https://expo.dev/)