Add a QR-Code on the final step

[nicolocarpignoli]

On the final step, as we have the live URL from Github, we can easily create a QR-Code pointing to that URL and show it in order for students/users/visitors to reach it without even typing the URL address. This JS library works great in order to create QRCodes: https://www.npmjs.com/package/qrcode-with-logos.