doc: added the rootdir parameter to hy_sack_create().
doc: added the rootdir parameter to hy_sack_create().

Conan-Kudo/libhif,rpm-software-management/libdnf,edynox/libdnf,hughsie/libhif,edynox/libdnf,cgwalters/libhif,rpm-software-management/libhif,Conan-Kudo/libhif,rpm-software-management/libdnf,cgwalters/libhif,hughsie/libhif,Conan-Kudo/libhif,cgwalters/libhif,Conan-Kudo/libhif,edynox/libdnf,hughsie/libhif,rpm-software-management/libhif,rpm-software-management/libhif,edynox/libdnf,hughsie/libhif,rpm-software-management/libdnf,cgwalters/libhif,rpm-software-management/libdnf,rpm-software-management/libhif