Add Story section to README for Todo App narrative

[Copilot]

New Feature

Added a short story to the README, as requested, to complement the Todo App documentation with a narrative example.
This change is scoped to documentation only and introduces a dedicated Story section.

What does this feature do?

• Adds a new ## Story section in README.md
• Provides a concise narrative showing a user creating tasks, completing them, and seeing persistence after refresh

Why is this feature needed?

• Addresses the issue directly by creating story content in the README
• Improves onboarding readability by pairing feature docs with a concrete usage narrative

Implementation details

• File updated: README.md
• Change type: append-only documentation update below existing usage/persistence text
• Example snippet added:

## Story

Maya starts her day by opening the Todo App and listing three goals for the sprint. As she checks each one off, the app instantly updates her progress and keeps her focused. Before logging off, she refreshes the page and smiles when every task is still there, right where she left it.