[GeoJSON] geojson.org DNS

[Martin Daly]

Github Pages, where geojson.org is hosted, changed at the start of the year, and the old infrastructure is going away soon:

https://github.com/blog/1715-faster-more-awesome-github-pages

I have updated the custom DNS record for geojson.org to point to the new locations. The change has started to propagate, so please let me know if you have any problems.

Martin