Revert to ox-reveal (remove org-re-reveal)

ox-reveal is maintained again, and org-re-reveal was
exhibiting (wrong-type-argument wholenump -1) errors in some corner
cases.

modules/lang/org/contrib/present.el

@@ -11,10 +11,15 @@
 ;;
 ;;; Packages
 
-(use-package! org-re-reveal
+(use-package! ox-reveal
   :after ox
   :init
-  (setq org-re-reveal-root "https://revealjs.com"))
+  ;; Fix #1127, where ox-reveal adds an errant entry to
+  ;; `org-structure-template-alist'
+  (setq org-reveal-note-key-char nil)
+  :config
+  (setq org-reveal-root "https://cdn.jsdelivr.net/npm/reveal.js@3/"
+        org-reveal-mathjax t))
 
 
 (use-package! org-tree-slide

modules/lang/org/packages.el

@@ -71,7 +71,7 @@
     :recipe (:host github :repo "anler/centered-window-mode")
     :pin "24f7c5be9d")
   (package! org-tree-slide :pin "7bf09a02bd")
-  (package! org-re-reveal :pin "14df7542f2"))
+  (package! ox-reveal :pin "aafedfd805"))
 (when (featurep! +journal)
   (package! org-journal :pin "128f0533a7"))