Nuget.Org now supports .snupkg packages for portable PDBs, replacing the old symbols.nupkg format.

https://blog.nuget.org/20181116/Improved-debugging-experience-with-the-NuGet-org-symbol-server-and-snupkg.html

Additionaly, since we use myget for staging prerelease packages, it would be great if pushing to an upstream source also pushed the symbol package, if present.