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/sys/tuist.go

@@ -1,21 +1,21 @@
 package sys
 
 import (
-	"github.com/versenilvis/iris/commands/core"
+	"github.com/versenilvis/iris/spec"
 )
 
 func init() {
-	core.Register(&core.Spec{
+	spec.Register(&spec.Spec{
 		Name:        "tuist",
 		Description: "Build the project in the current directory",
-		Subcommands: []core.Subcommand{
+		Subcommands: []spec.Subcommand{
 			{Name: "build", Description: "Build the project in the current directory"},
 			{Name: "warm", Description: "Warms the local and remote cache"},
 			{Name: "print-hashes", Description: "Print the hashes of the cacheable frameworks in the given project"},
 			{Name: "template", Description: "Name of template you want to use"},
 			{Name: "list", Description: "Lists available scaffold templates"},
 		},
-		Options: []core.Option{
+		Options: []spec.Option{
 			{Name: "--build-output-path", Description: "Build the project to a specific device, example usage: 'tuist build --device \\"},
 			{Name: "--os", Description: "Build the project to a specific OS, example usage: 'tuist build --os 14.0':"},
 			{Name: "--path", Description: "The path to the directory that contains the project whose targets will be cached"},