fix #12: Do not query nominatim so often when opening the home page
- Each time opening the home page causes ~ 20 requests to nominatim, letting the user IP getting blocked very fast
- The original intention seems to be to display the most recent 20 reviews, but they were not shown at all in my case (maybe due to other errors)
- We limit this to 3 reviews which should be much more friendly for the nominatim servers