Add link to this repository on the Amsterdam App 'about' page and website

[siccovansas]

This repository is currently not easy to find as it is not linked to from within the app nor from https://www.amsterdam.nl/contact/amsterdam-app/. It would be great if a link to this repo is added in both places.

[RikSchefferAmsterdam]

Thank you for your suggestion.

For now we added a link to https://app.amsterdam.nl. We will explore the possibilities of adding it to the mentioned places as well.