Added live table as current

Author: wwyc

sql/moz-fx-data-shared-prod/fenix_derived/clients_city_seen_v1/metadata.yaml

@@ -1,5 +1,6 @@
 friendly_name: Fenix Clients City Seen
 description: |-
+  This table captures the first and last seen geo attributes for each client_id and normalized channel.
 owners:
   - [email protected]
 labels: