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/pocketbase.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:        "pocketbase",
 		Description: "PocketBase CLI",
-		Subcommands: []core.Subcommand{
+		Subcommands: []spec.Subcommand{
 			{Name: "help", Description: "Help about any command"},
 			{Name: "migrate", Description: "Executes DB migration scripts"},
 			{Name: "folder", Description: "Migrations folder"},
@@ -21,7 +21,7 @@ func init() {
 			{Name: "string", Description: "API HTTP server address"},
 			{Name: "strings", Description: "CORS allowed domain origins list"},
 		},
-		Options: []core.Option{
+		Options: []spec.Option{
 			{Name: "--http", Description: "API HTTP server address"},
 			{Name: "--https", Description: "API HTTPS server address (auto TLS via Let's Encrypt)"},
 			{Name: "--origins", Description: "CORS allowed domain origins list (default [*])"},