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/arch.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:        "arch",
 		Description: "32-bit intel",
-		Options: []core.Option{
+		Options: []spec.Option{
 			{Name: "-arch", Description: "Print architecture type or run select architecture"},
 			{Name: "-32", Description: "Add the native 32-bit architecture to the list of architectures"},
 			{Name: "-64", Description: "Add the native 64-bit architecture to the list of architectures"},