Update wof:coterminous and wof:hierarchy_label descriptions

[stepps00]

As part of a localadmin/locality update in whosonfirst-data/whosonfirst-data-admin-us#86, it was noted that the current descriptions for the wof:coterminous and wof:hierarchy_label properties could be improved:

. Update the whosonfirst-properties repo with a better description for wof:coterminous and wof:hierarchy_label. >When both are set on a record, special considerations should be made so users are not appending extra information to an address string.