[GHC] #8551: Fix formatting in docs at one place

[GHC]

#8551: Fix formatting in docs at one place
------------------------------------+-------------------------------------
       Reporter:  Tarrasch          |             Owner:
           Type:  task              |            Status:  new
       Priority:  lowest            |         Milestone:
      Component:  Compiler          |           Version:  7.6.3
       Keywords:                    |  Operating System:  Unknown/Multiple
   Architecture:  Unknown/Multiple  |   Type of failure:  None/Unknown
     Difficulty:  Unknown           |         Test Case:
     Blocked By:                    |          Blocking:
Related Tickets:                    |
------------------------------------+-------------------------------------
 See to-be-attached patch

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8551>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler