NuGet Docs: Improve documentation on creating native packages about home

[tebeco]

the post don't elaborate regarding the orignal comment that got posted
it barely mention this:

The \build folder can be used for all NuGet packages and not just native packages. The \build folder respects target frameworks just like the \content, \lib, and \tools folders. This means you can create a \build\net40 folder and a \build\net45 folder and NuGet will import the appropriate props and targets files into the project. (Use of PowerShell scripts to import MSBuild targets is not needed.)

which don't clarify:

• what each folders does and what it role is
• how to do that from dotnet pack and not manually crafting magic folder
• how to single pack both Native + their managed wrapper
• how the sub folder scaffolding works with dedicated RID
• how to target dedicated TFM in case or ns2.0 / net8.0