Document that lonboard works with Panel about lonboard HOT 1 OPEN

Thanks for trying out lonboard! I'm not familiar with panel, but glad to see that it works! Happy to add that to the docs or whatever makes sense.

When you select a new colormap, alpha, anything... the map element fully reloads... that's pretty bad. In particular, that seems really bad because all the map data will be re-parsed and re-rendered from scratch (and maybe even re-downloaded?). lonboard's architecture assumes that you have a stateful jupyter widget on the JS side, and so changing a colormap or the alpha should not create a new map. In particular, if things are wired up correctly, changing the alpha should be instantaneous (especially if you link the alpha to the opacity attribute of the layer, instead of re-generating the colormap colors)

I'm not familiar with panel but there should be a way to persist an existing widget and mutate its state. You don't want to be creating a new map element from create_map each time.

from lonboard.