Add copyright and elevation metadata

[yz3440]

#43

[VctorAHernndez]

Hi @robolyst and @yz3440! I'm just wondering if there's any documentation around the units (i.e. m, ft, etc.) of the elevation data that comes from the scraper? As well as if the elevation relative to the ground, car or even sea level.

Also, what would the value of storing the copyright field be? Does it allow us to identify the source of the image (i.e. user-generated vs. Google-generated)?

Thanks in advance