This PR adds a story for the `ApplicationMenu` so it can be viewed in
isolation.

<img width="664" alt="Screenshot 2024-07-08 at 4 45 24 PM"
src="https://github.com/zed-industries/zed/assets/1486634/dca3dd32-4845-4009-b781-b4bac9ba6049">

Release Notes:

- N/A