docs: Issue in page Backup

[mikliapko]

I would like to report an issue in page https://manager.docs.scylladb.com/branch-3.2/sctool/backup

Problem

Wrong parameter name - name instead of <bucket>

https://manager.docs.scylladb.com/stable/sctool/backup.html#l-location

Suggest a fix

Replace name by <bucket>

[rayakurl]

@tzach - FYI. I assigned this issue to you, feel free to re-assign to the owner. Thanks