Internal data types are not linked in monarch-py documentation

[ptgolden]

While working on #820, I noticed something fishy with the monarch-py documentation. In the Python documentation generated by mkdocstrings, internal monarch-py classes listed as function parameters and return values are not linked to any documentation. For example, in the documentation for get_associations, there is no hint what AssociationCategory, AssociationPredicate, AssociationResult, or CompactAssociation are. Some (but not all) of these have applicable LinkML documentation (e.g. https://monarch-app.monarchinitiative.org/Data-Model/CompactAssociation/).