Implement AR feature for mobile (idea)

[julizet]

When out in the street, it could be interesting to look around with your phone in AR mode: with the trees depicted as pins, possibly with additional information such as tree type, amount of water in the past month, etc.

AR.js does Augmented Reality for the web and has been improving a lot recently, they now also have a feature to depict items based on geolocation.

https://ar-js-org.github.io/AR.js-Docs/

[yannickoo]

@julizet I just found this issue here - really cool idea which can be very useful when walking around the city. I'm not sure how easy it will be to integrate this into the existing codebase but maybe we could also just launch a separated app on a subdomain e.g. ar.giessdienkiez.de to build the experience there.