lang/org: use correct todo keyword on M-RET

Previously, new TODO headers created with M-RET or M-S-RET (bound to
+org/insert-item) would use the first TODO keyword in org-todo-keywords
in the new header. This wouldn't necessarily match the previous header.
e.g.

* [ ] Item 1
* TODO |

This fix ensures new headers will preserve the correct header, even if
the previous one is in a DONE state.

* [ ] Item 1
* [ ] |

modules/lang/org/autoload/org.el

@@ -203,8 +203,9 @@ wrong places)."
                 (save-excursion
                   (insert "\n")
                   (if (= level 1) (insert "\n")))))
-             (when (org-element-property :todo-type context)
-               (org-todo 'todo))))
+             (when-let* ((todo-keyword (org-element-property :todo-keyword context)))
+               (org-todo (or (get-text-property 0 'org-todo-head todo-keyword)
+                             'todo)))))
 
           (t (user-error "Not a valid list, heading or table")))