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/sys/sam.go

@@ -1,14 +1,14 @@
 package sys
 
 import (
-	"github.com/versenilvis/iris/commands/core"
+	"github.com/versenilvis/iris/spec"
 )
 
 func init() {
-	core.Register(&core.Spec{
+	spec.Register(&spec.Spec{
 		Name:        "sam",
 		Description: "Host of locally emulated Lambda container",
-		Subcommands: []core.Subcommand{
+		Subcommands: []spec.Subcommand{
 			{Name: "init", Description: "Init an AWS SAM application"},
 			{Name: "text", Description: "Template name"},
 			{Name: "validate", Description: "Validate an AWS SAM template"},
@@ -27,7 +27,7 @@ func init() {
 			{Name: "pipeline", Description: "Manage the continuous delivery of the application"},
 			{Name: "bootstrap", Description: "Generates the required AWS resources to connect your CI/CD system"},
 		},
-		Options: []core.Option{
+		Options: []spec.Option{
 			{Name: "--config-env", Description: "Host of locally emulated Lambda container"},
 			{Name: "--container-host-interface", Description: "Additional arguments to be passed to the debugger"},
 			{Name: "--debugger-path", Description: "Host path to a debugger to mount into the Lambda container"},