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/pulumi.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:        "pulumi",
 		Description: "The name of the stack to operate on. Defaults to the current stack",
-		Subcommands: []core.Subcommand{
+		Subcommands: []spec.Subcommand{
 			{Name: "about", Description: "Print information about the Pulumi environment"},
 			{Name: "cancel", Description: "Cancel a stack’s currently running update, if any"},
 			{Name: "config", Description: "Manage configuration"},
@@ -59,7 +59,7 @@ func init() {
 			{Name: "watch", Description: "[PREVIEW] Continuously update the resources in a stack"},
 			{Name: "whoami", Description: "Displays the username of the currently logged in user"},
 		},
-		Options: []core.Option{
+		Options: []spec.Option{
 			{Name: "-s", Description: "The name of the stack to operate on. Defaults to the current stack"},
 			{Name: "-y", Description: "Skip confirmation prompts, and proceed with cancellation anyway"},
 			{Name: "-j", Description: "Emit output as JSON"},