fix(org): respect org-insert-heading-hook in +org--insert-item

Doom replaces `org-insert-heading`, but its replacement does not respect
`org-insert-heading-hook`. This commit fixes that, enabling folks to
customize their insert-heading behavior, e.g.  adding a time stamp:

  (defun my/org-set-creation-date-heading-property ()
    (save-excursion
      (org-back-to-heading)
      (org-set-property "CREATED" (format-time-string "[%Y-%m-%d %T]"))))
  (add-hook 'org-insert-heading-hook #'my/org-set-creation-date-heading-property)

Ref: https://git.savannah.gnu.org/cgit/emacs/org-mode.git/tree/lisp/org.el#n6187
Ref: https://git.savannah.gnu.org/cgit/emacs/org-mode.git/tree/lisp/org.el#n1615

modules/lang/org/autoload/org.el

@@ -90,6 +90,7 @@
             (org-back-to-heading)
             (insert (make-string level ?*) " ")
             (save-excursion (insert "\n"))))
+         (run-hooks 'org-insert-heading-hook)
          (when-let* ((todo-keyword (org-element-property :todo-keyword context))
                      (todo-type    (org-element-property :todo-type context)))
            (org-todo