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/nest.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:        "nest",
 		Description: "Report actions that would be taken without writing out results",
-		Subcommands: []core.Subcommand{
+		Subcommands: []spec.Subcommand{
 			{Name: "new", Description: "Creates a new nest project"},
 			{Name: "project", Description: "The name of the project"},
 			{Name: "generate", Description: "Generate and/or modifies files based on a schematic"},
@@ -37,7 +37,7 @@ func init() {
 			{Name: "info", Description: "Display Nest project details"},
 			{Name: "update", Description: "Update Nest dependencies"},
 		},
-		Options: []core.Option{
+		Options: []spec.Option{
 			{Name: "-d", Description: "Report actions that would be taken without writing out results"},
 			{Name: "-p", Description: "Project in which to generate files"},
 			{Name: "--flat", Description: "Enforce flat structure of generated element"},