doctl-databases-*: add page (#10882)

* doctl-databases-*: add page

---------

Co-authored-by: Reinhart Previano Koentjoro <reinhart_previano@yahoo.com>
Co-authored-by: Juri Dispan <juri.dispan@posteo.net>
Co-authored-by: K.B.Dharun Krishna <kbdharunkrishna@gmail.com>

pages/common/doctl-databases-replica.md

@@ -0,0 +1,24 @@
+# doctl databases replica
+
+> Manage read-only replicas associated with a database cluster.
+> More information: <https://docs.digitalocean.com/reference/doctl/reference/databases/replica/>.
+
+- Run a `doctl databases replica` command with an access token:
+
+`doctl databases pool {{command}} --access-token {{access_token}}`
+
+- Retrieve information about a read-only database replica:
+
+`doctl databases replica get {{database_id}} {{replica_name}}`
+
+- Retrieve list of read-only database replicas:
+
+`doctl databases replica list {{database_id}}`
+
+- Create a read-only database replica:
+
+`doctl databases replica create {{database_id}} {{replica_name}}`
+
+- Delete a read-only database replica:
+
+`doctl databases replica delete {{database_id}} {{replica_name}}`