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/atlas.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:        "atlas",
 		Description: "CLI tool to manage MongoDB Atlas",
-		Subcommands: []core.Subcommand{
+		Subcommands: []spec.Subcommand{
 			{Name: "config", Description: "Manage your profile to store access settings for your MongoDB deployment"},
 			{Name: "init", Description: "Configure a profile to store access settings for your MongoDB deployment"},
 			{Name: "set", Description: "Configure specific properties of a profile"},
@@ -60,7 +60,7 @@ func init() {
 			{Name: "backup", Description: "Manage cloud backups for your project"},
 			{Name: "snapshot", Description: "Manage cloud backup snapshots for your project"},
 		},
-		Options: []core.Option{
+		Options: []spec.Option{
 			{Name: "--gov", Description: "Create a default profile for atlas for gov"},
 			{Name: "--output", Description: "Return a specific profile"},
 			{Name: "--force", Description: "Manage the CLI's authentication state"},