doc: updated the readme and created a new placeholder migration guide for v4

Author: pmathew92

README.md

@@ -26,21 +26,21 @@
 
 ### Requirements
 
-Android API version 31 or later and Java 8+.
+Android API version 31 or later and Java 17+.
 
 > :warning: Applications targeting Android SDK version 30 (`targetSdkVersion = 30`) and below should use version 2.9.0.
 
-Here’s what you need in `build.gradle` to target Java 8 byte code for Android and Kotlin plugins respectively.
+Here's what you need in `build.gradle` to target Java 17 byte code for Android and Kotlin plugins respectively.
 
 ```groovy
 android {
     compileOptions {
-        sourceCompatibility JavaVersion.VERSION_1_8
-        targetCompatibility JavaVersion.VERSION_1_8
+        sourceCompatibility JavaVersion.VERSION_17
+        targetCompatibility JavaVersion.VERSION_17
     }
 
     kotlinOptions {
-        jvmTarget = '1.8'
+        jvmTarget = '17'
     }
 }
 ```

V4_MIGRATION_GUIDE.md

@@ -0,0 +1,70 @@
+# Migration Guide from SDK v3 to v4
+
+## Overview
+
+v4 of the Auth0 Android SDK includes significant build toolchain updates to support the latest Android development environment. This guide documents the changes required when migrating from v3 to v4.
+
+## Requirements Changes
+
+### Java Version
+
+v4 requires **Java 17** or later (previously Java 11).
+
+Update your `build.gradle` to target Java 17:
+
+```groovy
+android {
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_17
+        targetCompatibility JavaVersion.VERSION_17
+    }
+
+    kotlinOptions {
+        jvmTarget = '17'
+    }
+}
+```
+
+### Gradle and Android Gradle Plugin
+
+v4 requires:
+
+- **Gradle**: 8.10.2 or later
+- **Android Gradle Plugin (AGP)**: 8.8.2 or later
+
+Update your `gradle/wrapper/gradle-wrapper.properties`:
+
+```properties
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.10.2-all.zip
+```
+
+Update your root `build.gradle`:
+
+```groovy
+buildscript {
+    dependencies {
+        classpath 'com.android.tools.build:gradle:8.8.2'
+    }
+}
+```
+
+### Kotlin Version
+
+v4 uses **Kotlin 2.0.21** . If you're using Kotlin in your project, you may need to update your Kotlin version to ensure compatibility.
+
+```groovy
+buildscript {
+    ext.kotlin_version = "2.0.21"
+}
+```
+
+## Breaking Changes
+
+
+## Getting Help
+
+If you encounter issues during migration:
+
+- [GitHub Issues](https://github.com/auth0/Auth0.Android/issues) - Report bugs or ask questions
+- [Auth0 Community](https://community.auth0.com/) - Community support
+- [Migration Examples](https://github.com/auth0/auth0.android/blob/main/EXAMPLES.md) - Updated code examples