Implement Basic Route for Update User by ID

[reimannsarah]

What this is

This task is to implement a basic route for updating a user by ID using Express routing.

Context

Clients should be able to update existing user data.

Acceptance Criteria

• A PUT route /users/:id is created.
• On request, the user data is read from the "data" directory using the FileSystem module.
• The API updates the user data with the new data from the request body.
• The updated user data is written back to the "data" directory using the FileSystem module.
• The API sends a JSON object containing the updated user data in the response.