Adds the Install-VSCode.ps1 script to signing (#1749)

* test signing Install-VSCode

* copy install-vscode to output

* Updated signing.xml

Author: TylerLeonhardt

tools/releaseBuild/Image/build.ps1

@@ -11,3 +11,4 @@ else {
 push-location C:/vscode-powershell
 Invoke-Build GetExtensionData,Clean,Build,Test,CheckPreview,Package
 Copy-Item -Verbose -Recurse "C:/vscode-powershell/PowerShell-insiders.vsix" "${target}/PowerShell-insiders.vsix"
+Copy-Item -Verbose -Recurse "C:/vscode-powershell/scripts/Install-VSCode.ps1" "${target}/Install-VSCode.ps1"

tools/releaseBuild/signing.xml

@@ -3,5 +3,7 @@
   <job platform="" configuration="" dest="__OUTPATHROOT__\signed" jobname="vscode powershell" approvers="vigarg;gstolt">
     <file src="__INPATHROOT__\release\out\PowerShell-insiders.vsix" signType="Vsix"
       dest="__OUTPATHROOT__\PowerShell-insiders.vsix" />
+    <file src="__INPATHROOT__\release\out\Install-VSCode.ps1" signType="Authenticode"
+      dest="__OUTPATHROOT__\Install-VSCode.ps1" />
   </job>
 </SignConfigXML>