Geo: Documentation is confusing over when and where to add the secondary nodes in /admin/geo_nodes

In https://docs.gitlab.com/ee/gitlab-geo/configuration.html#configuring-a-new-secondary-node, we say:

Do not add anything in the secondaries Geo nodes admin area (Admin Area ➔ Geo Nodes). This is handled solely by the primary node.

I was confused because this was suggesting that we shouldn't add the secondary Geo node at all. I think this was trying to say that the admin shouldn't add it in https://secondary.example.com/admin/geo_nodes.

It also wasn't clear to me on that page when the node should be added on the primary. This was buried in https://docs.gitlab.com/ee/gitlab-geo/database.html#step-2-add-the-secondary-gitlab-node. Perhaps we should mention that and/or prerequisites of starting that part?