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/stencil.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:        "stencil",
 		Description: "CLI to build Stencil projects and generate components",
-		Subcommands: []core.Subcommand{
+		Subcommands: []spec.Subcommand{
 			{Name: "build", Description: "Build components for development or production"},
 			{Name: "workers", Description: "Number of workers"},
 			{Name: "test", Description: "Run unit and end-to-end tests"},
@@ -17,7 +17,7 @@ func init() {
 			{Name: "off", Description: "Disable sharing anonymous usage data"},
 			{Name: "on", Description: "Enable sharing anonymous usage data"},
 		},
-		Options: []core.Option{
+		Options: []spec.Option{
 			{Name: "--ci", Description: "Set stencil config file"},
 			{Name: "--debug", Description: "Set the log level to debug"},
 			{Name: "--dev", Description: "Development build"},