[GHC] #13980: Broken ghc-flag links in the users guide

[GHC]

#13980: Broken ghc-flag links in the users guide
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        Reporter:  patrickdoc        |                Owner:  (none)
            Type:  bug               |               Status:  patch
        Priority:  normal            |            Milestone:
       Component:  Documentation     |              Version:  8.0.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Documentation     |  Unknown/Multiple
  bug                                |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D3778
       Wiki Page:                    |
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Comment (by bgamari):

 Thanks a lot for doing this, patrickdoc!

 If you are familiar with Sphinx, it would also be great to knock off
 #11654 so we can drop `mkUserGuidePart`. In principle I would even be okay
 with dropping the options summary table if that makes things easier (which
 would also issues like #12155 out of existance). However, the problem is
 we still need the flag descriptions for the manpage.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13980#comment:2>
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