add powershell az list parity with azure cli example

Add code so Azure PowerShell output is the same as the Azure CLI, which lists the AZs per region

Author: mbrat2005

articles/reliability/availability-zones-overview.md

@@ -76,6 +76,7 @@ az rest --method get \
 $subscriptionId = (Get-AzContext).Subscription.ID
 $response = Invoke-AzRestMethod -Method GET -Path "/subscriptions/$subscriptionId/locations?api-version=2022-12-01"
 $locations = ($response.Content | ConvertFrom-Json).value
+$locations | Where-Object {$null -ne $_.availabilityZoneMappings} | Select-Object -Property name,displayName,@{name='availabilityZoneMappings';expression={$_.availabilityZoneMappings | convertto-json}} | Format-List
 ```
 
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