add preamble into latex article export

lisp/my/my-org-letter.el

@@ -86,14 +86,16 @@
 (org-export-define-derived-backend 'letter-latex 'latex
 
   :menu-entry
-  '(?L "Export to LaTeX (Letter)"
-       ((?L "As LaTeX buffer" my-org-letter-latex-export-as-latex)
-	      (?l "As LaTeX file" my-org-letter-latex-export-to-latex)
-	      (?p "As PDF file" my-org-letter-latex-export-to-pdf)
-	      (?o "As PDF file and open"
+  '(?l ?l
+       (
+        ;;(?T "As LaTeX buffer" my-org-letter-latex-export-as-latex)
+	      ;;(?t "As LaTeX file" my-org-letter-latex-export-to-latex)
+	      (?t "As PDF-letter file" my-org-letter-latex-export-to-pdf)
+	      (?T "As PDF-letter file and open"
 	          (lambda (a s v b)
 	            (if a (my-org-letter-latex-export-to-pdf t s v b)
 		            (org-open-file (my-org-letter-latex-export-to-pdf nil s v b)))))))
+
   :options-alist
   '((:with-toc nil "toc" my-org-letter-export-with-toc)
     (:latex-class "LATEX_CLASS" nil my-org-letter-latex-default-class t)

settings/my-settings.el

@@ -8,6 +8,10 @@
     (add-hook 'org-mode-hook 'my-org-link-color-hook)
     (add-hook 'org-ctrl-c-ctrl-c-hook 'my-org-table-cell-color-attr)))
 
+(use-package my-org-article
+  :load-path "lisp/my"
+  :after (org))
+
 (use-package my-org-letter
   :load-path "lisp/my"
   :after (org))

settings/org-settings.el

@@ -9,6 +9,8 @@
 ;; https://tex.stackexchange.com/questions/282448/why-does-emacs-or-auctex-turns-into
 
 ;;; Commentary:
+;; `org-export-default-language'
+;; `org-options-keywords'
 
 ;; * Overview of modes and commands
 ;; --------------------------------
@@ -240,8 +242,10 @@ Example defines
   :init
   (setq org-export-backends '(ascii html icalendar latex md odt reveal tufte))
   :config
+  (setq org-startup-folded nil)                    ;; nil = showall = #+STARTUP: showall
   (setq org-startup-with-inline-images t)          ;; #+STARTUP: inlineimages|noinlineimages, show inline images when loading a new Org file
   (setq org-image-actual-width '(600))             ;; image width displayed in org
+  (setq org-tag-persistent-alist '(("ignore" . "i") ("noexport" . "n")))
   ;; todo see also org-todo-keyword-faces and org-superstar-todo-bullet-alist
   (setq org-todo-keywords                          ;; (x!) record a time stamp, (x@) add a note (with time), (y/z) entering the state / leaving the state
         '((sequence "TODO(t)" "WAIT(w)" "|" "DONE(d)" "CANC(c)")))