Clarify support for cross region Tiered Storage / RRR#942

kbatuigas merged 5 commits intomainredpanda-data/docs:mainfrom

DOC-809-Tiered-storage-recommendations-for-region-vs-multi-region-bucketsredpanda-data/docs:DOC-809-Tiered-storage-recommendations-for-region-vs-multi-region-bucketsCopy head branch name to clipboard