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/trivy.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:        "trivy",
 		Description: "Skip updating built-in policies [$TRIVY_SKIP_POLICY_UPDATE]",
-		Subcommands: []core.Subcommand{
+		Subcommands: []spec.Subcommand{
 			{Name: "image", Description: "Scan an image"},
 			{Name: "filesystem", Description: "Scan local filesystem for language-specific dependencies and config files"},
 			{Name: "rootfs", Description: "Scan rootfs"},
@@ -27,7 +27,7 @@ func init() {
 			{Name: "help", Description: "Shows a list of commands or help for one command"},
 			{Name: "version", Description: "Print the version"},
 		},
-		Options: []core.Option{
+		Options: []spec.Option{
 			{Name: "--skip-policy-update", Description: "Skip updating built-in policies [$TRIVY_SKIP_POLICY_UPDATE]"},
 			{Name: "--removed-pkgs", Description: "Input file path instead of image name [$TRIVY_INPUT]"},
 			{Name: "--config-policy", Description: "Clear image caches without scanning [$TRIVY_CLEAR_CACHE]"},