Add primary node clone URL to Geo secondary 'How to work faster with Geo' popover

Zendesk: https://gitlab.zendesk.com/agent/tickets/78412

Step 2 on this popover does not actually display the primary server's clone URL. @stanhu notes that this should be possible/easy now because of because of https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/2015

cc/ @brodock