haskell-yi-contrib: move under libraries instead

pkgs/top-level/haskell-packages.nix

···
 
   yi = callPackage ../applications/editors/yi/yi.nix { };
 
-  yiContrib = callPackage ../applications/editors/yi/yi-contrib.nix {};
+  yiContrib = callPackage ../development/libraries/haskell/yi-contrib {};
 
   yiLanguage = callPackage ../development/libraries/haskell/yi-language {};