Define and document the process for managing BEOC schedules

In the MR for adding the BEOC role to the handbook, the topic of BEOC scheduling came up as part of the discussion. Since BEOCs do not have the rigid scheduling requirements of EOCs, we need to decide if PD is the best way to manage BEOC schedules on a long term basis. There are a few options here:

• Agree a core set of hours per timezone and feed that into PD somehow to create a rotation
• Keep the second shift out of PD altogether and do a best effort help with @sre-oncall
• If we keep the second shift out of PD use a squad type thing for scheduling and a manual rotation?

To resolve this issue we need to:

1. discuss and decide on a scheduling method
2. implement the preferred method
3. document the scheduling method in the handbook.