Fix Admin Area path

doc/administration/admin_area.md

doc/administration/auth/ldap/ldap-troubleshooting.md

doc/administration/backup_restore/migrate_to_new_server.md

doc/administration/external_users.md

...stration/geo/disaster_recovery/background_verification.md

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

...nistration/geo/setup/two_single_node_external_services.md

doc/administration/geo/setup/two_single_node_sites.md

doc/administration/gitaly/praefect.md

doc/administration/maintenance_mode/index.md

doc/administration/operations/fast_ssh_key_lookup.md

doc/administration/pages/troubleshooting.md

doc/administration/settings/account_and_limit_settings.md

doc/administration/settings/continuous_integration.md

doc/administration/settings/jira_cloud_app.md

doc/administration/settings/push_event_activities_limit.md

doc/administration/settings/slack_app.md