added Ukrainian lang. file uk.yml, corrected uk:Ukrainian
added Ukrainian lang. file uk.yml, corrected uk:Ukrainian

openfoodfoundation/openfoodnetwork,mkllnk/openfoodnetwork,mkllnk/openfoodnetwork,openfoodfoundation/openfoodnetwork,openfoodfoundation/openfoodnetwork,mkllnk/openfoodnetwork,mkllnk/openfoodnetwork,openfoodfoundation/openfoodnetwork