docs: add instruction to set Cloud Scheduler region (#16)
docs: add instruction to set Cloud Scheduler region (#16)

* add instruction to set Cloud Scheduler region

* update according to review

Co-authored-by: Yiwen Gong <e8ede7765ba9fc5b77a5097b6a1b6092fe0e1c2a@google.com>
cloudspannerecosystem/scheduled-backups