Add README user story for Todo app usage

[Copilot]

The issue requested adding a story to the README. This PR introduces a concise narrative that demonstrates real-world Todo app usage and highlights the core user flow.

• What changed

  • Added a new ## Story: Midnight Release section to README.md.
  • Included a short scenario showing:
    • task creation and completion,
    • use of Active/Completed filters,
    • recovery after restart via localStorage,
    • cleanup with Clear Completed.

• Why this addresses the issue

  • Satisfies the request to “create a story” directly in the README.
  • Keeps the story aligned with the documented feature set and existing app behavior.

• Snippet added

  ## Story: Midnight Release
  
  On the night before launch, Maya opened the Todo App and listed every last task...