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-db.md

@@ -0,0 +1,24 @@
+# doctl databases db
+
+> Manage specific databases that are served by a database cluster.
+> More information: <https://docs.digitalocean.com/reference/doctl/reference/databases/db>.
+
+- Run a `doctl databases db` command with an access token:
+
+`doctl databases db {{command}} --access-token {{access_token}}`
+
+- Retrieve the name of the given database hosted in the given database cluster:
+
+`doctl databases db get {{database_id}} {{database_name}}`
+
+- List existing databases hosted within a given database cluster:
+
+`doctl databases db list {{database_id}}`
+
+- Create a database with the given name in the given database cluster:
+
+`doctl databases db create {{database_id}} {{database_name}}`
+
+- Delete the database with the given name in the given database cluster:
+
+`doctl databases db delete {{database_id}} {{database_name}}`