Changes in pandoc-crossref

[benoit-girard]

It seems that pandoc-crossref is now installed by default in:
~/Library/Haskell/bin/pandoc-crossref
So the compilation insctructions sould be udated (they refer to ~/.cabal/bin/pandoc-crossref)

[khinsen]

Looks like you are using macOS (like myself). I also had to adapt the path. But I suspect the path given in the instructions is the right one under Linux. @rougier, can you confirm?

[rougier]

I'm not sure. This path does not work anymore for me. Using --filter pandoc-crossref is fine.
I think I introduced it if several crossref packages are installed.