Copy _app.tsx and _document.tsx within the Root Layout

[boodland]

Sub issue of #702

App router uses a Root layout which is defined at the top of the app directory and applies to all routes. We need to copy/migrate the contents of _app.tsx and _document.tsx to the root layout so they are applied for the app route.

This issue also migrate meet-the-team page in order to check that the new app route logic works as expected