Refine Round Robin description in multidisk balancing

Clarify wording in the round robin

Author: eyyu

content/en/altinity-kb-setup-and-maintenance/multidisk-jbod-balancing.md

@@ -7,7 +7,7 @@ ClickHouse provides two options to balance an insert across disks in a volume wi
 
 ## **Round Robin (Default):**
 
-ClickHouse selects the next disk in a round robin manner to write each part created.
+ClickHouse selects the next disk in a round robin manner to write a part.
 
 This is the default setting and is most effective when parts created on insert are roughly the same size.