Update docs/configuring-playbook-synapse.md: on Synapse Admin

Based on docs/configuring-playbook-bot-draupnir.md

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

docs/configuring-playbook-synapse.md

@@ -147,7 +147,9 @@ Take a look at:
 
 ## Synapse Admin
 
-Certain Synapse administration tasks (managing users and rooms, etc.) can be performed via a web user-interace, if you install [Synapse Admin](configuring-playbook-synapse-admin.md).
+With [Synapse Admin](configuring-playbook-synapse-admin.md), certain Synapse administration tasks (managing users and rooms, etc.) can be performed via a web user-interace.
+
+The playbook can install and configure Synapse Admin for you. For details about it, see [this page](configuring-playbook-synapse-admin.md).
 
 ## Monitoring Synapse Metrics with Prometheus and Grafana