Update new PD schedule link with note
What
New link to RM PD Schedule per #20124 (comment 1977564359)
Why
We gave a try to manage the RM schedule for PD in Terraform, but the layer start dates and end dates being non-uniform (3rd Thursday of the month vs weekly) did not work well with PagerDuty API.
Moving to back to hand managed adding a layer per Region/Minor version release.