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/redwood.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:        "redwood",
 		Description: "Script",
-		Subcommands: []core.Subcommand{
+		Subcommands: []spec.Subcommand{
 			{Name: "side", Description: "Which side(s) to build"},
 			{Name: "api", Description: "Build the api server"},
 			{Name: "web", Description: "Build the web server"},
@@ -45,7 +45,7 @@ func init() {
 			{Name: "deploy", Description: "Setup auth configuration for a provider"},
 			{Name: "up", Description: "Executes outstanding data migrations"},
 		},
-		Options: []core.Option{
+		Options: []spec.Option{
 			{Name: "--forward", Description: "String of one or more Webpack Dev Server config options"},
 			{Name: "--side", Description: "Show help for command"},
 			{Name: "--build", Description: "Build (web) and Start (api) command for Render deploy"},