refactor(commands): separate commands and its core into two folders (#32)

- I think it would be better if one for commands only, one for the spec
handling core logic so people won't be confused by the core logic inside
the commands folder (cleaner I guess)
- Regen docs

commands/js/turbo.go

@@ -1,14 +1,14 @@
 package js
 
 import (
-	"github.com/versenilvis/iris/commands/core"
+	"github.com/versenilvis/iris/spec"
 )
 
 func init() {
-	core.Register(&core.Spec{
+	spec.Register(&spec.Spec{
 		Name:        "turbo",
 		Description: "Print the version",
-		Subcommands: []core.Subcommand{
+		Subcommands: []spec.Subcommand{
 			{Name: "bin", Description: "Get the path to the turbo binary"},
 			{Name: "link", Description: "Link your local directory to a Vercel organization and enable remote caching"},
 			{Name: "login", Description: "Login to your Vercel account"},
@@ -20,7 +20,7 @@ func init() {
 			{Name: "full", Description: "Show all output"},
 			{Name: "none", Description: "Hide process output"},
 		},
-		Options: []core.Option{
+		Options: []spec.Option{
 			{Name: "--version", Description: "Print the version"},
 			{Name: "--help", Description: "Print a help message"},
 			{Name: "--no-gitignore", Description: "Do not create or modify .gitignore"},