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/op.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:        "op",
 		Description: "Official 1Password CLI",
-		Subcommands: []core.Subcommand{
+		Subcommands: []spec.Subcommand{
 			{Name: "account", Description: "Manage your locally configured 1Password accounts"},
 			{Name: "add", Description: "Add an account to sign in to for the first time"},
 			{Name: "get", Description: "Get details about your account"},
@@ -42,7 +42,7 @@ func init() {
 			{Name: "update", Description: "Check for and download updates"},
 			{Name: "whoami", Description: "Get information about a signed-in account"},
 		},
-		Options: []core.Option{
+		Options: []spec.Option{
 			{Name: "--address", Description: "The sign-in address for your account"},
 			{Name: "--email", Description: "The email address associated with your account"},
 			{Name: "--raw", Description: "Only return the session token"},