Update docs/reference/commandline/service_create.md

Co-Authored-By: olljanat <[email protected]>

docs/reference/commandline/service_create.md

@@ -763,7 +763,7 @@ argument.
 Use the `--replicas-max-per-node` flag to set the maximum number of replica tasks that can run on a node.
 The following command creates a nginx service with 2 replica tasks but only one replica task per node.
 
-One example of where this can be useful is to balance tasks over a set of datacenters together with `--placement-pref`
+One example where this can be useful is to balance tasks over a set of data centers together with `--placement-pref`
 and let `--replicas-max-per-node` setting make sure that replicas are not migrated to another datacenter during
 maintenance or datacenter failure.