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/arduino_cli.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:        "arduino-cli",
 		Description: "Arduino CLI - build, compile, and upload Arduino sketches",
-		Subcommands: []core.Subcommand{
+		Subcommands: []spec.Subcommand{
 			{Name: "board", Description: "Arduino board commands"},
 			{Name: "FQBN", Description: "Fully qualified board name"},
 			{Name: "port", Description: "Arduino board port connection"},
@@ -53,7 +53,7 @@ func init() {
 			{Name: "upload", Description: "Upload Arduino sketches. This does NOT compile the sketch prior to upload"},
 			{Name: "version", Description: "Shows the version number of Arduino CLI which is installed on your system"},
 		},
-		Options: []core.Option{
+		Options: []spec.Option{
 			{Name: "--board-options", Description: "Max time to wait for port discovery, example: '30s, 1m (default 1s)'"},
 			{Name: "-b", Description: "Fully Qualified Board Name, example: 'arduino:avr:uno'"},
 			{Name: "-h", Description: "Help for attach"},