Minor updates to database reviewer docs

There was a small section of text that got lost in a suggestion
application

doc/development/database/database_reviewer_guidelines.md

@@ -32,6 +32,13 @@ Team members are encouraged to self-identify as database domain experts, and add
 projects:
   gitlab:
     - reviewer database
+```
+
+Create the merge request [using the "Database reviewer" template](https://gitlab.com/gitlab-com/www-gitlab-com/-/blob/master/.gitlab/merge_request_templates/Database%20reviewer.md),
+adding your expertise your profile YAML file. Assign to a database maintainer or the
+[Database Team's Engineering Manager](https://about.gitlab.com/handbook/engineering/development/enablement/database/).
+
+After the `team.yml` update is merged, the [Reviewer roulette](../code_review.md#reviewer-roulette)
 may recommend you as a database reviewer.
 
 ## Resources for database reviewers