Defines the code interface for a given resource + domain combination in the current module. For example:

defmodule MyApp.Accounting do
  require Ash.CodeInterface

  Ash.CodeInterface.define_interface(MyApp.Accounting, MyApp.Accounting.Transaction)
  Ash.CodeInterface.define_interface(MyApp.Accounting, MyApp.Accounting.Account)
  Ash.CodeInterface.define_interface(MyApp.Accounting, MyApp.Accounting.Invoice)
end