Upgrade Guide for v6.1.0 is not available

Hello.

By clicking on "Upgrade Guide" for version 6.1.0 - File not found error appears.

Release:
https://github.com/microsoftgraph/msgraph-sdk-java/releases/tag/v6.1.0

Address that doesn't contain the document.
https://github.com/microsoftgraph/msgraph-sdk-java/blob/dev/docs/upgrade-to-v6.md

Could you please restore it or provide a link to this document?

Thank you.