Fix manifest path

Author: jjonescz

scripts/PublishVsix.ps1

@@ -1,3 +1,3 @@
 $VisualStudio = & "${env:ProgramFiles(x86)}\Microsoft Visual Studio\Installer\vswhere.exe" -latest -prerelease -format json | ConvertFrom-Json
 $VsixPublisher = Join-Path -Path $VisualStudio.installationPath -ChildPath "VSSDK\VisualStudioIntegration\Tools\Bin\VsixPublisher.exe" -Resolve
-& $VsixPublisher publish -payload $env:vsix -publishManifest "$PSScriptRoot\vsix-publish.json" -personalAccessToken $env:MARKETPLACE_TOKEN
+& $VsixPublisher publish -payload $env:vsix -publishManifest "$PSScriptRoot\..\vsix-publish.json" -personalAccessToken $env:MARKETPLACE_TOKEN