feat: reastructure and create commands

pkg/invoice/invoice.go

@@ -45,11 +45,11 @@ func (s *Service) Generate(creditor, deptor model.Entity, mindur time.Duration,
 	)
 	html, err := r.ToHTML()
 	if err != nil {
-		return
+		return document, r, err
 	}
 
 	document, err = s.pdf.HtmlToPdf(html)
-	return
+	return document, r, err
 }
 
 func filter[T any](slice []T, ok func(T) bool) []T {