Merge branch 'docs_nw_geo_external_trackingdb' into 'master'

Update docs for an external Geo tracking database

See merge request gitlab-org/gitlab!69887

doc/administration/geo/setup/external_database.md

@@ -249,7 +249,7 @@ the tracking database on port 5432.
    gitlab-rake geo:db:create
    ```
 
-1. The reconfigure should automatically migrate the database. You can migrate the database manually if needed, for example if `gitlab_rails['auto_migrate'] = false`:
+1. The reconfigure should automatically migrate the database. You can migrate the database manually if needed, for example if `geo_secondary['auto_migrate'] = false`:
 
    ```shell
    gitlab-rake geo:db:migrate