chore(docs): upgrade doc intro

Author: dreamorosi

Diff for: docs/upgrade.md

@@ -3,5 +3,11 @@ title: Upgrade guide
 description: Guide to update between major Powertools for AWS Lambda (TypeScript) versions
 ---
 
+## Migrate to v2 from v1
+
+This release includes some breaking changes, please take some time to review this guide to make your transition to v2 as smooth as possible.
+
+### Quick summary
+
 !!! warning
     This guide is a work in progress. We'll update it as we get closer to the 2.0 release. If you have any questions, or want to follow the progress, please join the discussion on the [GitHub issue](https://github.com/aws-powertools/powertools-lambda-typescript/issues/1714).