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/pac.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:        "pac",
 		Description: "7",
-		Subcommands: []core.Subcommand{
+		Subcommands: []spec.Subcommand{
 			{Name: "admin", Description: "Work with your Power Platform Admin Account"},
 			{Name: "list", Description: "List all environments from your tenant"},
 			{Name: "create", Description: "Creates a Dataverse instance in your tenant"},
@@ -60,7 +60,7 @@ func init() {
 			{Name: "update-settings", Description: "Update environment settings"},
 			{Name: "package", Description: "Commands for working with Dataverse package projects"},
 		},
-		Options: []core.Option{
+		Options: []spec.Option{
 			{Name: "--environment", Description: "List all environments that contain given string in their name or ID"},
 			{Name: "--type", Description: "List all environments with the given type"},
 			{Name: "--name", Description: "List all environments that contain given string in their name"},