Add migration guide for flutter

Author: dhananjayj-dev

fern/docs/pages/plug-sdk/flutter.mdx

@@ -291,3 +291,24 @@ DevRev.processPushNotification(jsonEncode(payload));
 
 - **Issue**: Not receiving push notifications.  
 	**Solution**: Ensure that your app is configured to receive push notifications and that your device is registered with the DevRev SDK.
+
+## Migration Guide
+
+This guide will help you transition from the legacy UserExperior SDK to the new DevRev SDK in your Flutter application. Below is a feature equivalence chart and detailed instructions for migrating.
+
+### Feature Equivalence Chart
+
+| Feature | UserExperior SDK | DevRev SDK |
+|-|-|-|
+| Installation | `user_experior: ^<version>` | `devrev_sdk_flutter: ^<version>` |
+| Initialization | `userExperior.startRecording(appID)` | `DevRev.configure(appID)` |
+| User Identification | `userExperior.setUserIdentifier(userIdentifier)` | `DevRev.identifyAnonymousUser(userID)`<br>`DevRev.identifyUnverifiedUser(userID, organizationID)`<br>`DevRev.identifyVerifiedUser(userID, sessionToken)`<br>`DevRev.logout(deviceID)` |
+| Event Tracking | `userExperior.logEvent(name)` | `DevRev.trackEvent(name, properties)` |
+| Session Recording | `userExperior.stopRecording()`<br>`userExperior.pauseRecording()`<br>`userExperior.resumeRecording()` | `DevRev.startRecording()`<br>`DevRev.stopRecording()`<br>`DevRev.pauseRecording()`<br>`DevRev.resumeRecording()`<br>`DevRev.processAllOnDemandSessions()` |
+| Opting in/out | `userExperior.optOut()`<br>`userExperior.optIn()`<br>`userExperior.getOptOutStatus()` | `DevRev.stopAllMonitoring()`<br>`DevRev.resumeAllMonitoring()` |
+| Session Properties | `userExperior.setUserProperties(properties)` | `DevRev.addSessionProperties(properties)`<br>`DevRev.clearSessionProperties()` |
+| Timers | `userExperior.startTimer(timerName, properties)`<br>`userExperior.endTimer(timerName, properties)` | `DevRev.startTimer(name, properties)`<br>`DevRev.endTimer(name, properties)` |
+| PLuG support chat | Not supported. | `DevRev.showSupport()`<br> `DevRev.createSupportConversation()` |
+| Push Notifications | Not supported. | `DevRev.registerDeviceToken(deviceID, deviceToken)`<br>`DevRev.unregisterDevice(deviceID)` |
+
+---