fix(emacs-lisp): Doom API demos in help(ful) docs

Due to cd26975, `with-file-contents!` leaves the cursor at point-min,
not point-max, so this `re-search-backward` call would never find its
mark. Now, the elisp demos for Doom functions/macros should show up
again in helpful-*/describe-* buffers.

Amend: cd269753cf

modules/lang/emacs-lisp/autoload.el

@@ -392,7 +392,7 @@ Intended as :around advice for `elisp-demos--search'."
     (or (funcall fn symbol)
         (with-file-contents! (doom-path doom-docs-dir "examples.org")
           (save-excursion
-            (when (re-search-backward
+            (when (re-search-forward
                    (format "^\\*+[ \t]+\\(?:TODO \\)?%s$"
                            (regexp-quote (symbol-name symbol)))
                    nil t)