[lang] Fixes PUBLISH_DIR for api-quick-start
[lang] Fixes PUBLISH_DIR for api-quick-start

Since api-quick-start publish location (api-guide/quick-start) is
different from standard scheme, we need to explicit PUBLISH_DIR
for translated api-quick-start documents.

Change-Id: I36d54d618a7ae0f32f5b8d86488b540f1be997c6

openstack/openstack-doc-tools,openstack/openstack-doc-tools