Merge pull request #6295 from fullenw1/patch-1

Update New-AzureRmAvailabilitySet.md

Author: Maddie Clayton

src/ResourceManager/Compute/Commands.Compute/help/New-AzureRmAvailabilitySet.md

@@ -139,7 +139,12 @@ Accept wildcard characters: False
 ```
 
 ### -Sku
-The Name of Sku
+The Name of Sku.
+The acceptable values for this parameter are:
+
+- Aligned: For managed disks
+- Classic: For unmanaged disks
+
 ```yaml
 Type: String
 Parameter Sets: (All)