Minor tweaks to improve nugetizability

[kzu]

Add this targets file alongside Directory.Build.targets named Directory.Build.targets.user (which will now be ignored in commits):

<Project>

  <PropertyGroup>
    <RestoreSources>https://pkg.kzu.io/index.json;https://api.nuget.org/v3/index.json</RestoreSources>
  </PropertyGroup>

  <ItemGroup>
    <PackageVersion Update="NuGetizer" Version="42.42.42-main.807" />
  </ItemGroup>

</Project>

This adds the CI nugetizer package feed and the latest build from main, which contains the fix for platform-suffixed target frameworks: devlooped/nugetizer#306

[bijington]

That's an impressive package version number! It has strong Hitchikers vibes...

[dansiegel]

Thanks @kzu tested this and it resolves the packing issue for the Configuration package!