Added optional content guidance on edit sms template view
Added optional content guidance on edit sms template view
alphagov/notifications-admin,alphagov/notifications-admin,gov-cjwaszczuk/notifications-admin,alphagov/notifications-admin,gov-cjwaszczuk/notifications-admin,gov-cjwaszczuk/notifications-admin,alphagov/notifications-admin,gov-cjwaszczuk/notifications-admin