Finalizing the Integration of Cobra into Multi-git

Refactor the main.go file

With the root command fully implemented, we need to refactor the main.go file, so it executes the Cobra root command instead of all the work it’s currently doing.

The location of main.go should also change. At the moment, it is in cmd/mg/main.go, but Cobra applications have a main.go file at the top-level directory of the project.

The main.go is very simple, and it just executes the root command:

package main

import "github.com/the-gigi/multi-git/cmd"

func main() {
	cmd.Execute()
}

The only unique thing about main.go is that it uses the Go module name to import the cmd package where ...