Fixing anchors in GHC docs

I think I sent this out already, but never heard back. An issue was fixed in HsColour regarding HTML anchors in the GHC docs, documented here: https://github.com/haskell/hackage-server/issues/319 Apparently GHC devs upload their own documentation [to hackage], which means HsColour needs to be updated on your end so that anchors are correct the next time docs are generated. -Eric