Update CHANGELOG.md

Author: minbi

CHANGELOG.md

@@ -3,7 +3,7 @@
 ## 2.5.0
 ### General Updates
 * **All Services**
-	* Swift 3 documentation and naming definitions added. The naming definitions will affect all Swift users by changing method names. Please refer to the [blog](https://aws.amazon.com/blogs/mobile/aws-mobile-sdk-for-ios-version-2-5-0-improvements-and-changes-to-swift-support/) for more details.
+	* Swift 3 documentation and naming definitions added. The naming definitions will affect all Swift users by changing method names. Please refer to the [blog](https://aws.amazon.com/blogs/mobile/aws-mobile-sdk-for-ios-version-2-5-0-improvements-and-changes-to-swift-support/) for more details on changes and how to upgrade from 2.4.X to 2.5.X.
 * **SDK Core**
 	* `AWSRegionType` and `AWSServiceType` enums do not follow the convention that uses lowercase at the beginning. Example: `.USEast1` and `.DynamoDB`
 * **Updated AWSTask**