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/forge.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:        "forge",
 		Description: "A command line interface for managing Atlassian-hosted apps",
-		Subcommands: []core.Subcommand{
+		Subcommands: []spec.Subcommand{
 			{Name: "autocomplete", Description: "Configures autocomplete for the Forge CLI"},
 			{Name: "create", Description: "Create an app"},
 			{Name: "deploy", Description: "Deploy your app to an environment"},
@@ -31,7 +31,7 @@ func init() {
 			{Name: "webtrigger", Description: "Get a web trigger URL"},
 			{Name: "whoami", Description: "Display the account information of the logged in user"},
 		},
-		Options: []core.Option{
+		Options: []spec.Option{
 			{Name: "--verbose", Description: "Enable verbose mode"},
 			{Name: "-h", Description: "Display help for command"},
 			{Name: "-t", Description: "Specify the template to use"},