Update docs/configuring-playbook-prometheus-grafana.md: move up the note about creating a CNAME record

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

docs/configuring-playbook-prometheus-grafana.md

@@ -8,6 +8,8 @@ By default, this playbook installs Grafana web user-interface on the `stats.` su
 
 When setting, replace `example.com` with your own.
 
+**Note**: It is possible to install Prometheus without installing Grafana. This case it is not required to create the CNAME record.
+
 ## Adjusting the playbook configuration
 
 ### Configure Prometheus
@@ -81,8 +83,6 @@ grafana_hostname: grafana.example.com
 
 After changing the domain, **you may need to adjust your DNS** records to point the Grafana domain to the Matrix server.
 
-**Note**: It is possible to install Prometheus without installing Grafana. This case it is not required to create the CNAME record.
-
 ## Installing
 
 After configuring the playbook and potentially [adjusting your DNS records](#adjusting-dns-records), run the playbook with [playbook tags](playbook-tags.md) as below: