Remove API site information
Remove API site information

The api-guide is now in openstack-manuals and api-site does not get
translated anymore, remove section.

Also, update link for project-info.

Make this dependent on 678463 to test that publishing of PDFs works.

Depends-On: https://review.opendev.org/678463
Change-Id: I1ca036fb853dfc86284b173a41829e973b582800

openstack/i18n,openstack/i18n