small grammar fix per Acrolinx

Author: American-Dipper

articles/virtual-desktop/create-host-pools-powershell.md

@@ -144,7 +144,7 @@ To successfully domain-join, do the following things on each virtual machine:
 
 ## Register the virtual machines to the Azure Virtual Desktop host pool
 
-Registering the virtual machines to a Azure Virtual Desktop host pool is as simple as installing the Azure Virtual Desktop agents.
+Registering the virtual machines to an Azure Virtual Desktop host pool is as simple as installing the Azure Virtual Desktop agents.
 
 To register the Azure Virtual Desktop agents, do the following on each virtual machine: