rationalized directories/documentation

chains can only contain known arrows

modelling the retraction category

beginnings of having composition laws

verifying arrow sources/targets

initial FiniteCategory code

sorted out use of SetsWithSlowActions

nonsense about CRLFs

minor note on coset geometries

updated to Scala 3.7.0

notes on coset geometries

updated but not very performant card shuffling

making Auto-to-Dot conversions implicit

tidying up

an optionator for automorphisms