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/okta.go

@@ -1,14 +1,14 @@
 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:        "okta",
 		Description: "The Okta CLI is the easiest way to get started with Okta!",
-		Subcommands: []core.Subcommand{
+		Subcommands: []spec.Subcommand{
 			{Name: "register", Description: "Sign up for a new Okta account"},
 			{Name: "login", Description: "Authorizes the Okta CLI tool"},
 			{Name: "apps", Description: "Manage Okta apps"},
@@ -21,7 +21,7 @@ func init() {
 			{Name: "help", Description: "Displays help information about the specified command"},
 			{Name: "generate-completion", Description: "Generate bash/zsh completion script for Okta"},
 		},
-		Options: []core.Option{
+		Options: []spec.Option{
 			{Name: "--company", Description: "Company/organization used when registering a new Okta account"},
 			{Name: "--email", Description: "Email used when registering a new Okta account"},
 			{Name: "--first-name", Description: "First name used when registering a new Okta account"},