Hot backup information is missing

I couldn't find anything about hot backups for leveled or leveldb in the docs. From the 3.0.16 release notes: `A fix to timeouts in leveled hot backups` so it's clearly been around for a while.
https://www.tiot.jp/riak-docs/riak/kv/3.0.16/using/cluster-operations/backing-up/ is missing the leveled storage location