Cobra and Viper are great together, but it's not uncommon to use them apart.
New Cobra users don't know better and including Viper by default adds complexity to the skeleton.

It's questionable that a default license makes any sense from a legal perspective.
If the tool created the license without the user choosing it, then it may not even be applicable.
Best to let the user choose their license with intent.

Pretty major change in behavior, but with modules a change is needed.
Now cobra can initialize and add from within any Go module.
The experience is simplified and streamlined, but requires `go mod init` to happen first.

Merging the updated documentation from the user_guide into the cobra/README.md.
Adding links as appropriate to both guides.