Updates in doc instructions

-1 broken link and another change, in 78140ca1 whose scenario I'm not exactly sure of, but this change from .Iterable to .abc.Iterable when dealing with collections object was necessary on my Ubuntu 22.04 machine to enjoy a proper local build of the html doc. You will let me know

(Time to consider to build the doc on sthg else than Ubuntu 18 in our pipeline ?)