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/js/deno.go

@@ -1,14 +1,14 @@
 package js
 
 import (
-	"github.com/versenilvis/iris/commands/core"
+	"github.com/versenilvis/iris/spec"
 )
 
 func init() {
-	core.Register(&core.Spec{
+	spec.Register(&spec.Spec{
 		Name:        "deno",
 		Description: "A modern JavaScript and TypeScript runtime",
-		Subcommands: []core.Subcommand{
+		Subcommands: []spec.Subcommand{
 			{Name: "bench", Description: "Run benchmarks"},
 			{Name: "bundle", Description: "Bundle module and dependencies into single file"},
 			{Name: "cache", Description: "Cache the dependencies"},
@@ -34,7 +34,7 @@ func init() {
 			{Name: "vendor", Description: "Vendor remote modules into a local directory"},
 			{Name: "help", Description: "Print this message or the help of the given subcommand(s)"},
 		},
-		Options: []core.Option{
+		Options: []spec.Option{
 			{Name: "--import-map", Description: "Load import map file"},
 			{Name: "-c", Description: "Specify the configuration file"},
 			{Name: "--no-check", Description: "Skip type-checking modules"},