update info on single zone for multi cluster when creating a machine pool

Author: fmcdonal

modules/creating-a-machine-pool-cli.adoc

@@ -81,7 +81,7 @@ $ rosa create machinepool --cluster=<cluster-name> \
                           --taints=<key>=<value>:<effect>,<key>=<value>:<effect> \ <6>
                           --use-spot-instances \ <7>
                           --spot-max-price=0.5 <8>
-                          --availability-zone=<az> <9>
+                          --availability-zone=<availability_zone_name> <9>
 ----
 <1> Specifies the name of the machine pool. Replace `<machine_pool_id>` with the name of your machine pool.
 <2> Enables autoscaling in the machine pool to meet the deployment needs.
@@ -91,7 +91,7 @@ $ rosa create machinepool --cluster=<cluster-name> \
 <6> Optional: Defines the taints for the machine pool. Replace `<key>=<value>:<effect>,<key>=<value>:<effect>` with a key, value, and effect for each taint, for example `--taints=key1=value1:NoSchedule,key2=value2:NoExecute`. Available effects include `NoSchedule`, `PreferNoSchedule`, and `NoExecute`.
 <7> Optional: Configures your machine pool to deploy machines as non-guaranteed AWS Spot Instances. For information, see link:https://aws.amazon.com/ec2/spot/[Amazon EC2 Spot Instances] in the AWS documentation. If you select *Use Amazon EC2 Spot Instances* for a machine pool, you cannot disable the option after the machine pool is created.
 <8> Optional: If you have opted to use Spot Instances, you can specify this argument to define a maximum hourly price for a Spot Instance. If this argument is not specified, the on-demand price is used.
-<9> Optional: For Multi-AZ clusters, you can create a machine pool in a Single-AZ of your choice. Replace `<az>` with a Single-AZ.
+<9> Optional: For Multi-AZ clusters, you can create a machine pool in a Single-AZ of your choice. Replace `<az>` with a Single-AZ name.
 +
 [IMPORTANT]
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