[PR] The proj files have been updated to enable SourceLink

[JTOne123]

CSProj files have been updated to enable SourceLink in your nuget

[This pull request was created with an automated workflow]

I noticed that your repository and Nuget package are important for our .NET community, but you still haven't enabled SourceLink.

We have to take 2 steps:

1. Please approve this pull request and make .NET a better place for .NET developers and their debugging.
2. Then just upload the .snupkg file to https://www.nuget.org/ (now you can find the snupkg file along with the .nuget file)

You can find more information about SourceLine at the following links
https://github.com/dotnet/sourcelink
https://www.hanselman.com/blog/ExploringNETCoresSourceLinkSteppingIntoTheSourceCodeOfNuGetPackagesYouDontOwn.aspx

If you are interesting about this automated workflow and how it works
https://github.com/JTOne123/GitHubMassUpdater

If you notice any flaws, please comment and I will try to make fixes manually

[paulirwin]

Sorry for this PR being closed due to renaming the default branch. This has been merged into develop for the upcoming 4.0 release. Thanks for the contribution!