Merge pull request #91 from OpenZeppelin/monitor-migration-docs

chore: Adding info about monitor migration

Author: tirumerla

content/defender/index.mdx

@@ -11,6 +11,15 @@ New sign-ups were disabled on June 30, 2025. Until the final shutdown on July 1,
 
 </Callout>
 
+<Callout type='info' title='Migration Guides Available'>
+
+- **[Migrate from Defender Monitor to OpenZeppelin Monitor](/defender/migration#monitor-migration)** - Export configurations, set up infrastructure, and test your monitors
+- **[Migrate from Defender Relayer to OpenZeppelin Relayer](/defender/migration#relayer-migration)** - Transfer relayers, update SDK integration, and migrate transaction handling
+
+View the complete [Migration Guide](/defender/migration) for detailed instructions.
+
+</Callout>
+
 OpenZeppelin Defender is a mission-critical developer security platform to **code**, **audit**, **deploy**, **monitor**, and **operate** blockchain applications with confidence.
 
 Integrating directly into the developer workflow, Defender makes it easy and fast for developers and operators to prevent and fix security issues pre and post-deployment.