Unfold hidden subtree after doom-completing-read-org-headings

Affects doom/help* commands, as well as +default/org-notes-headlines,
and others (any command that uses doom-completing-read-org-headings to
search org files).

core/autoload/help.el

@@ -174,7 +174,12 @@ selection of all minor-modes, active or not."
           (cond ((functionp location)
                  (funcall location))
                 (location
-                 (goto-char location))))
+                 (goto-char location)))
+          (ignore-errors
+            (when (outline-invisible-p)
+              (save-excursion
+                (outline-previous-visible-heading 1)
+                (org-show-subtree)))))
       (user-error "Aborted"))))
 
 ;;;###autoload