v4.0.0

Contented 4.0.0 is here 🎉

This release represents a complete overhaul of the library, based on two principles:

1. Keeping a direct correspondence between run-time and a compile-time types
2. Decoupling the representation of a run-time type from its use

As a consequence of 1., Contented provides run-time counterparts of primitive, literal, and compound types. Because of 2., such run-time representations do not carry any information about their future use in their type. For instance, string is of type Type<string>.