alphabet → concept Relation

File in seqan3/alphabet	Includes file in seqan3/core/concept
concept.hpp	cereal.hpp
concept.hpp	core_language.hpp
composite / alphabet_tuple_base.hpp	core_language.hpp
composite / alphabet_tuple_base.hpp	tuple.hpp
composite / detail.hpp	core_language.hpp
detail / alphabet_proxy.hpp	core_language.hpp