add an option to prettyprint call descriptions, etc.

[RichMorin]

I often find myself editing Dialyzer's output to make the structure clearer. For example, I might edit this call description:

InfoToml.CheckItem.check_values_h(
  _inp_map :: %{atom() | binary() => %{atom() | binary() => binary() | map()}},
  _check_fn :: (_, _ -> [any()]),
  []
)

into something like this:

InfoToml.CheckItem.check_values_h(
  _inp_map :: %{
    atom() | binary() => %{
      atom() |
      binary() => binary() |
      map()
    }
  },
  _check_fn :: (_, _ -> [any()]),
  []
)

So, I'd like to suggest a --pretty mode that would do this automagically.