A value is made from its JSON by looking its type up here; what a value reads as where a
primitive is consumed is asked here too. The built-in kinds are registered when the SDK loads;
a host registers its own the same way. A type nobody has registered still loads and saves: it
becomes an RichDataRegistry.Unmodeled value that carries its JSON as it was and reads as
nothing.
The kinds of rich data a cell can hold, by type.
Remarks
A value is made from its JSON by looking its
typeup here; what a value reads as where a primitive is consumed is asked here too. The built-in kinds are registered when the SDK loads; a host registers its own the same way. A type nobody has registered still loads and saves: it becomes an RichDataRegistry.Unmodeled value that carries its JSON as it was and reads as nothing.