Support for merging NuGet packages.config files
NuGet package files are simple XML files, and the merge procedure should be reasonably simple too.
Packages are keyed by ID, so if there's a collision based on the ID, take the package reference with the highest version number.
If the two sources include unique packages, the result should be the union of the two.
Ralf Koban commented
Please note that support of merging NuGet files is not that easy as you also need to consider and update the versions inside of the Visual Studio project files.