Multi-tenant migration steps for Hibernate ORM

## Communication goals (e.g. detailed howto vs orientation)

How to use Citus as a backend for multi-tenant Spring applications. Follow the usual migration outline from the other frameworks. Consult the linked blog post for details.

### Good locations for content in docs structure

New page within
https://docs.citusdata.com/en/v7.4/develop/migration.html

### Are there relevant blog posts or outside documentation about the concept/feature?

https://www.citusdata.com/blog/2018/02/13/using-hibernate-and-spring-to-build-multitenant-java-apps/