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/aliases.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:        "aliases",
 		Description: "Prints help information",
-		Subcommands: []core.Subcommand{
+		Subcommands: []spec.Subcommand{
 			{Name: "add", Description: "Add an alias via the cli"},
 			{Name: "name", Description: "The name of the alias"},
 			{Name: "command", Description: "The command you want to run"},
@@ -30,7 +30,7 @@ func init() {
 			{Name: "move", Description: "Move a user up or down the prioritization list"},
 			{Name: "use", Description: "Assign a user to the top of the priority list"},
 		},
-		Options: []core.Option{
+		Options: []spec.Option{
 			{Name: "--help", Description: "Prints help information"},
 			{Name: "--version", Description: "Prints version information"},
 			{Name: "-E", Description: "Whether to enable the user if they are not currently enabled"},