message: Fixes method call typo
diff: @@ -87,7 +87,7 @@ Because both the `getContainer` and `createContainer` methods are async, the `st
  ```js
  async function start() {
  if (location.hash) {
  - await loadExistingDice(location.hash.substring[1])
  + await loadExistingDice(location.hash.substring(1))
  } else {
  const id = await createNewDice();
  location.hash = id;
  