[Haskell] Data.Traversable

[Dominik Schrempf]

Hello,

I was repeating the properties of some basic type classes yesterday and ended up
reading through the "Overview" section in 'Data.Traversable'. I was deeply
impressed and wondered why I hadn't noticed it before, and so I realized, it is
there since base-4.15.0.0. I wanted to deeply thank whoever took the time to
write this up. In my opinion, we need more of this in the Haddocks, and on
Hackage.

Thank you!

Dominik

PS: I also noticed that when reading Haddocks of the 'base-4.15.0.0' package on
Hackage, the link 'Contents' on the top right does not link to the usual
overview about the package including all package versions, but only to the
contents of the documentation of the current version. I liked the general
overview about package versions more.