Exploring the new rollForward and allowPrerelease settings in global.json: Exploring ASP.NET Core 3.0 - Part 8

I was listening to the Azure DevOps Podcast with Jeffrey Palermero recently and heard Kathleen Dollard mention that there were some updates to the global.json file and .NET Core SDK in 3.0. This post explores those additions and the effects they have on SDK selection for a machine with multiple SDKs installed.