2. As a user, I want to be able to navigate to all the pages in the application by clicking the links in the nav bar

[fullybaked]

Summary

Users need to be able to navigate between the pages of our application in order to access all of its features. There is a navigation bar in the Layout.jsx component, but it's not quite feature-complete: the links in the nav element don't actually allow the user to navigate from page to page.

Acceptance criteria

• The nav element is added to the Layout component
• Links to the "Home", "List", and "Add item" pages of the app are In the nav element
• The links all function as expected using the NavLink component from react-router-dom

Notes

• The official docs for the NavLink component will come in very handy!
• While a standard anchor element (<a>) could allow a user to navigate from page to page, the NavLink component adds additional behavior that is essential to our app functioning correctly!