Higher deloopings of abelian groups

[UlrikBuchholtz]

We could include a further discussion of deloopings of abelian groups (and homomorphisms) between them, after David Wärn (https://arxiv.org/abs/2301.03685) and bandings (https://arxiv.org/abs/2301.02636). In particular, the type of torsors of a pointed type, which agrees with the type of banded types for central types.