Geo docs: Update file names with `Node`

doc/administration/geo/disaster_recovery/planned_failover.md

...disaster_recovery/runbooks/planned_failover_multi_node.md

...isaster_recovery/runbooks/planned_failover_single_node.md

doc/administration/geo/replication/configuration.md

...stration/geo/replication/img/adding_a_secondary_v13_3.png

...dministration/geo/replication/img/geo_dashboard_v14_0.png

...inistration/geo/replication/img/geo_site_health_v14_0.png

doc/administration/geo/replication/troubleshooting.md