authorship

Stream: general

[Yury G. Kudryashov]

In #3285 I move some code to new files, namely directed is now here and well_founded_iff_no_descending_seq is now here.

Do I understand correctly that directed was written by @Johannes Hölzl and well_founded_iff_no_descending_seq was written by @Mario Carneiro ? If someone else wants to be mentioned in "Authors" of these files, please tell me.