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/yalc.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:        "yalc",
 		Description: "Work with yarn/npm packages locally like a boss",
-		Subcommands: []core.Subcommand{
+		Subcommands: []spec.Subcommand{
 			{Name: "publish", Description: "Copy all the files that should be published in remote NPM registry"},
 			{Name: "add", Description: "Copy the current version from the store to your project"},
 			{Name: "package", Description: "The package you want to add"},
@@ -22,7 +22,7 @@ func init() {
 			{Name: "restore", Description: "Restore retreated packages"},
 			{Name: "retreat", Description: "Remove packages from project, but leave in lock file (to be restored later)"},
 		},
-		Options: []core.Option{
+		Options: []spec.Option{
 			{Name: "--push", Description: "Publish without running scripts"},
 			{Name: "--no-sig", Description: "Disable adding hash signature of all files when copying package content"},
 			{Name: "--content", Description: "Show included files in the published package"},