IGNITE-12951 Update documents for migrated extensions

[Saikat Maitra]

Hi,

I have raised a PR for the below jira issue.

https://issues.apache.org/jira/browse/IGNITE-12951 - Update documents for
migrated extensions

PR : https://github.com/apache/ignite-website/pull/85

Please review and share feedback.

Regards,
Saikat