Add powershell script for attaching a harddisk to a guest

plugins/providers/hyperv/scripts/attach_disk_drive.ps1

@@ -0,0 +1,19 @@
+#Requires -Modules VagrantMessages
+
+param(
+    [Parameter(Mandatory=$true)]
+    [string]$VmId,
+    [string]$ControllerType,
+    [string]$ControllerNumber,
+    [string]$ControllerLocation,
+    [Parameter(Mandatory=$true)]
+    [string]$DiskFilePath
+)
+
+try {
+    $vm = Hyper-V\Get-VM -Id $VmId
+    Hyper-V\Add-VMHardDiskDrive -VMName $vm -ControllerType $ControllerType -ControllerNumber $ControllerNumber -ControllerLocation $ControllerLocation -Path $DiskFilePath
+} catch {
+    Write-ErrorMessage "Failed to attach disk ${DiskFilePath} to VM ${vm}: ${PSItem}"
+    exit 1
+}