fixing doc string

playbooks/roles/supervisor/tasks/main.yml

@@ -25,6 +25,7 @@
 #    - supervisor_log_dir
 #    - supervisor_venv_dir
 #    - supervisor_service_user
+#    - supervisor_service
 #
 # Dependencies:
 #   - common
@@ -46,7 +47,7 @@
 #    supervisor_log_dir: /path/to/supervisor/log/dir
 #    supervisor_venv_dir: /path/to/supervisor/venv/dir
 #    supervisor_service_user: user to run supervisor as
-#    supervisor_service_name: upstart-service-name
+#    supervisor_service: upstart-service-name
 #
 ---
 - name: supervisor | create application user