Update Set-AzureRmContext.md

Author: cormacpayne

src/ResourceManager/Profile/Commands.Profile/help/Set-AzureRmContext.md

@@ -164,8 +164,7 @@ Accept wildcard characters: False
 ```
 
 ### -Subscription
-Subscription Name or Id 
-Whie using subscription Id as the parameter, this parameter is alias as -SubscriptionId 
+The name or id of the subscription that the context should be set to. This parameter has aliases to -SubscriptionName and -SubscriptionId, so, for clarity, either of these can be used instead of -Subscription when specifying name and id, respectively.
 
 ```yaml
 Type: System.String