Added specification for single menu item

[nileshkumar0]

What/Why/How?

What
Adds a GET operation to /menu/{menuItemId} so clients can fetch a single menu item by ID.

Why
The path already supported DELETE, but there was no way to retrieve one item directly. This completes the single-resource menu item API and aligns with patterns like GET /orders/{orderId}.

How
Updated openapi/paths/menu_{menuItemId}.yaml to define getMenuItem:

Public read access (security: []), consistent with GET /menu
200 response returns the existing MenuItem schema
Standard error responses: 400, 404, 500

Reference

Path registration: openapi/openapi.yaml → /menu/{menuItemId}
Related operations:
GET /menu — list menu items
DELETE /menu/{menuItemId} — delete menu item (requires menu:write)
GET /menu-item-images/{menuItemId} — fetch menu item photo

Testing

Ran npm test (redocly lint) — spec validates successfully
Previewed docs locally with npm start and confirmed GET /menu/{menuItemId} appears under Products
(Optional) Verified against live API if available: GET https://api.cafe.redocly.com/menu/{menuItemId}

Screenshots (optional)

Check yourself

Code is linted (npm test passes)
Tested (OpenAPI lint validation)
All new/updated code is covered with tests (N/A — OpenAPI spec change; lint is the project’s test suite)

Security

Security impact of change has been considered — read-only endpoint, no auth required (same as GET /menu)
Code follows company security practices and guidelines — reuses shared response refs; write operations remain protected via OAuth2 (menu:write)