(Emacs/app|lang)~pdf-tools is disabled, dired-guess-shell pdf zathura

I find pdf-tools really slow in comparison to zathura, with very
little benefit to it being integrated into Emacs.  Zathura is faster,
leaner and more fit for purpose.

PDFs, if a shell command may be invoked on them in dired, now show
zathura as a default argument.

Emacs/.config/emacs/app.org

@@ -217,6 +217,7 @@ are some corners I'd like to adjust).
                  (dired "~/Text/PDFs/"))
           :which-key "Open PDFs"))
   :config
+  (add-to-list 'dired-guess-shell-alist-user '("\\.pdf\\'" "zathura"))
   (defun +dired/insert-all-subdirectories ()
     "Insert all subdirectories currently viewable."
     (interactive)
@@ -247,7 +248,6 @@ are some corners I'd like to adjust).
     "m" #'dired-mark-files-regexp
     "u" #'dired-undo))
 #+end_src
-
 ** fd-dired
 Uses fd for finding file results in a directory: ~find-dired~ ->
 ~fd-dired~.

Emacs/.config/emacs/lang.org

@@ -68,7 +68,10 @@ asset.
 For example if I were editing an org document which I was eventually
 compiling into a PDF, my workflow would be much smoother with a PDF
 viewer within Emacs that I can open on another pane.
-** PDF tools
+** WAIT PDF tools
+:PROPERTIES:
+:header-args:emacs-lisp: :tangle no
+:END:
 ~pdf-tools~ provides the necessary functionality for viewing PDFs.
 There is no proper PDF viewing without this package.
 ~evil-collection~ provides a setup for this mode, so use that.