Make :doc ModuleName print module docs.
E.g.
ghci> :doc Prelude
-- |
-- Module : Prelude
-- Copyright : (c) The University of Glasgow 2001
-- License : BSD-style (see the file libraries/base/LICENSE)
--
-- Maintainer : libraries@haskell.org
-- Stability : stable
-- Portability : portable
--
-- The Prelude: a standard module. The Prelude is imported by default
-- into all Haskell modules unless either there is an explicit import
-- statement for it, or the NoImplicitPrelude extension is enabled.
--
as :doc
prints docstrings as is (which is fine).