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/remotion.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:        "remotion",
 		Description: "Create videos programmatically in React",
-		Subcommands: []core.Subcommand{
+		Subcommands: []spec.Subcommand{
 			{Name: "versions", Description: "Prints and validates versions of all Remotion packages"},
 			{Name: "gpu", Description: "Prints information about how Chrome uses the GPU"},
 			{Name: "compositions", Description: "Prints the list of available compositions"},
@@ -50,7 +50,7 @@ func init() {
 			{Name: "benchmark", Description: "Try different render configurations and compare them"},
 			{Name: "install", Description: "Ensure Remotion dependencies"},
 		},
-		Options: []core.Option{
+		Options: []spec.Option{
 			{Name: "--props", Description: "Pass input props as filename or as JSON"},
 			{Name: "--env-file", Description: "Specify a location for a dotenv file"},
 			{Name: "--disable-headless", Description: "Run Chrome in normal mode rather than headless"},