Update docs/configuring-playbook-bridge-matrix-bridge-sms.md: add the common section "Troubleshooting"

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

docs/configuring-playbook-bridge-matrix-bridge-sms.md

@@ -61,3 +61,7 @@ ansible-playbook -i inventory/hosts setup.yml --tags=setup-all,ensure-matrix-use
 ## Usage
 
 Read the [user guide](https://github.com/benkuly/matrix-sms-bridge/blob/master/README.md#user-guide) to see how this bridge works.
+
+## Troubleshooting
+
+As with all other services, you can find the logs in [systemd-journald](https://www.freedesktop.org/software/systemd/man/systemd-journald.service.html) by logging in to the server with SSH and running `journalctl -fu matrix-sms-bridge`.