Document how deep inheritance can go

## Problem

I have a use case where a base model needs subclasses who also have subclasses. From the examples of InheritanceManager in the docs, it’s not clear if that is supported.

Start with the InheritanceManager examples in the documentation and inspect how inheritance is described. Determine whether a base model can have subclasses that also have subclasses, then document the supported behavior and add an example or clarification so readers can tell whether deep inheritance is supported.

Written by the indexing model from the issue text.