Following the rules defined here: https://remix.run/docs/en/main/pages/v2
Run the following in the project directory:
curl -fsSL https://gist.github.com/Plopix/58fc3f3be202d9915c466e71077d36a2/raw/migrate-to-v2-routing.bash | bash -s I_ROUTES_FOLDER O_ROUTES_FOLDER