This hook is used to get the JSONLD extended schema for a given type name.

By default, it creates Stub schema-definition for each type in the schema. The stub definition lacks all relations, to avoid infinite recursion when rendering the schema. It also adds the

properties to the schema.

An alternative extension method can be provided to the app context, which will be used instead of the default one if present.

It brings the definition of the given typeName to the top of the schema.