Reinstate Master-Replica wording
Polishing Fix lettercasing.
Refrain from racist/oppressive language where possible #1308 Rename Master to Upstream and leftover Slave to Replica.
Adapt documentation to changed terminology for master/replica #845
Fixed type, where _at-least-once_ was used instead of _at-most-once_
Updated Command execution reliability (asciidoc)
Convert to Asciidoc