URL does not update when layer is chosen

[jidanni]

1. Visit https://geojson.io/#map=18/24.177045/120.720867
2. Move the map around.
3. Observe the URL in the browser URL bar updating.
4. Now see the bar at the bottom of the screen,
   Standard Standard Satellite Standard Light Standard Dark Outdoors OSM
   and pick one.
5. Alas, the URL does not update.
6. Contrast this with OSM.ORG website, where the URL will contain the layer we chose. That makes it possible to share maps featuring any layer, not just the standard layer!
7. Same problem with the Globe Mercator buttons.