URLs in Docs are broken

[kreba]

First off, thanks for putting this library out there! ❤️

While reading the documentation I realized that many links in the text as well as URLs in the example code are broken, probably due to reorganization of the assets.

See https://github.com/mapbox/mapboxgl-jupyter/blob/master/docs/viz.md

[ryanbaumann]

Thanks for the bug report @kreba!