Layers priority

[bdbmax]

Let me know if I missed it and it's already a possible option!

It would be great to be able to declare some type of layers priority, e.g. a layer of lines always appearing over a choropleth layer. An option could be a new argument like 'before_id' where we could specify before which layer the new layer should appear. I think it's which array appears before which?

[anthonynorth]

Layer rendering order is currently handled by index. First layer added is rendered on the bottom (above the basemap).

Interleaved deckgl and mapboxgl layers is planned. This will add support for before_id, which could be a mapboxgl or deckgl layer.