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/ops/oci.go

@@ -1,14 +1,14 @@
 package ops
 
 import (
-	"github.com/versenilvis/iris/commands/core"
+	"github.com/versenilvis/iris/spec"
 )
 
 func init() {
-	core.Register(&core.Spec{
+	spec.Register(&spec.Spec{
 		Name:        "oci",
 		Description: "Oracle Cloud Infrastructure CLI",
-		Subcommands: []core.Subcommand{
+		Subcommands: []spec.Subcommand{
 			{Name: "compute", Description: "Manage Compute resources like instances and images"},
 			{Name: "instance", Description: "Manage Compute instances"},
 			{Name: "launch", Description: "Launch a new compute instance"},
@@ -35,7 +35,7 @@ func init() {
 			{Name: "alarm", Description: "Manage monitoring alarms"},
 			{Name: "budget", Description: "Manage Budgets and Cost Controls"},
 		},
-		Options: []core.Option{
+		Options: []spec.Option{
 			{Name: "--availability-domain", Description: "The availability domain of the instance"},
 			{Name: "--compartment-id", Description: "The OCID of the compartment"},
 			{Name: "--shape", Description: "The shape of the instance"},