Add basic map to exploration page

[marekrogala]

@wojdziw I think this is a great task for you :)

Goal: Display photos on a map - the more photos the bigger point on the map. Map needs to work offline.

These looks like good resources how to do that:

• https://digitalki.net/2017/12/13/offline-maps-with-mapbox-gl-js-and-electron/
• https://github.com/osm2vectortiles/offline-maps

Potential alternative in case of problems with the above: https://github.com/kothic/kothic-js

We need map tiles for Gabon, or ideally for entire Africa or Earth.

[wojdziw]

i managed to lay some grounds for this and created a separate task - #40, hope that's fine :)

[wojdziw]

this task might be about adding photos from the data source

[marekrogala]

@wojdziw 👍 great, so once #40 is done, this task will be about displaying photo locations on the map