Describe the option you'd like to add
#209 added support for leading arrows, but one thing people might prefer is a mixture of leading/trailing, where only the thin arrows are leading. Why?

• :: is next to function name, for greppability
• Can use trailing haddocks for arguments
• Friendlier diffs when adding explicit forall or constraints

Show a code example exemplifying the different option settings

-- trailing
foo ::
  forall a.
  (C1, C2) =>
  Int ->
  String ->
  Bool

-- leading
foo
  :: forall a
  . (C1, C2)
  => Int
  -> String
  -> Bool

-- only-args
foo ::
  forall a.
  (C1, C2) =>
     Int
  -> String
  -> Bool