We need to document how every field type is interacted with from the REST API, similar to what is done for the PHP Field Type reference. That reference can be part of the REST reference, or part of the Field Type reference, both are acceptable.

For each field type, we need examples of both output and input structures (<value />). These may slightly differ from the PHP reference, depending on the field type (for instance, image or rich text).

In addition, some more advanced field types may use extra endpoints. These should also be documented or linked to from the type's REST reference.