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/mongocli.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:        "mongocli",
 		Description: "CLI tool to manage your MongoDB Cloud",
-		Subcommands: []core.Subcommand{
+		Subcommands: []spec.Subcommand{
 			{Name: "config", Description: "Configure a profile to store access settings for your MongoDB deployment"},
 			{Name: "set", Description: "Configure specific properties of a profile"},
 			{Name: "ls", Description: "List available profiles"},
@@ -60,7 +60,7 @@ func init() {
 			{Name: "disable", Description: "Disable the application-managed slow operation threshold for your project"},
 			{Name: "log", Description: "Download host logs for your project"},
 		},
-		Options: []core.Option{
+		Options: []spec.Option{
 			{Name: "--output", Description: "Return a specific profile"},
 			{Name: "--force", Description: "MongoDB Atlas operations"},
 			{Name: "--accessListIp", Description: "IP address to be allowed to access the deployment"},