Outdated documentation for foldl and friends

Straight from Data.Foldable, here is the documentation for foldl:

    -- | Left-associative fold of a structure.
    --
    -- @'foldl' f z = 'Prelude.foldl' f z . 'toList'@

But, of course, Prelude.foldl is the same foldl!

There are other functions with similar problems.

When revising these, please put in (back?) examples of how these work, at least on lists. I've been doing functional programming for some time, and I still like to look at examples to make sure that I'm getting my foldl and foldr straight. Maybe it's because my brain is small, but we don't want to exclude people with small brains!