Should we use JSON.NET for non-.NET core

[stevehansen]

As it was used more for .NET 4.8 it might create less dependencies

https://github.com/stevehansen/RecordCommander/blob/80252da8cc181ac9f22d1166846032c3b13495a6/RecordCommander/RecordCommander.csproj#L27-L29
https://github.com/stevehansen/RecordCommander/blob/80252da8cc181ac9f22d1166846032c3b13495a6/RecordCommander/RecordCommandRegistry.cs#L326