How to build Microsoft.Windowsdesktop.App package

Hi, I arranged the directory structure like this:

```
${rootdir}
|------> wpf
|------> runtime
|------> windowsdesktop
```

Then I entered the windowsdesktop subdirectory and ran:

```
cd windowsdesktop
.\build.cmd -pack -c Release
```

This generated a package at:
```
artifacts\packages\Release\Shipping\windowsdesktop-runtime-8.0.11-win-x64.zip
```

However, after extracting this ZIP package, I found that the PresentationCore.dll MD5 hash is different from the one in wpf/artifacts.

Where is the library in the windowsdesktop package coming from?
How can I pack my custom PresentationCore.dll in windowsdesktop-runtime-8.0.11-win-x64.zip