Improve docs for 'ghc-shared-options'.
Improve docs for 'ghc-shared-options'.

Heather/cabal,sopvop/cabal,garetxe/cabal,gbaz/cabal,bennofs/cabal,themoritz/cabal,mydaum/cabal,sopvop/cabal,headprogrammingczar/cabal,bennofs/cabal,gbaz/cabal,kolmodin/cabal,mydaum/cabal,sopvop/cabal,kolmodin/cabal,thomie/cabal,themoritz/cabal,themoritz/cabal,thomie/cabal,garetxe/cabal,headprogrammingczar/cabal,Heather/cabal