Iron 867 fixing framework

[mee-ironsoftware]

• Including SixLabors.ImageSharp.Drawing and SixLabors.Fonts into lib folder
• Update copyright

[jacob-mellor]

Looks good to me. Do we need to document how to use IronDrawing in framework projects?
Ideally finding a way to do this without users having to do special config for the IDE would be a big win

[mee-ironsoftware]

For using Framework project, User need to switch from packages.config to PackageReference.
Default Visual Studio is packages.config old style.
So, user can be done by Tools > Options > NuGet Package Manager > General > Default package management format.