Test lonboard with JupyterBook outputs, make example

[JupyterBook](https://jupyterbook.org/) is a great way to create "computational narratives" as nice looking static webpages from Jupyter notebooks, using [MyST](https://mystmd.org/) as the parsing and rendering engine.

It would be nice to ensure that `lonboard` maps work in the JupyterBook static outputs and provide some documentation and examples.

I think a lot might "just work" out of the box, and it would be good to test what happens currently if you have a `lonboard`-based map in your notebook and render it via JupyterBook. I think steps might be roughly:

- Create a simple test notebook using `lonboard` and a simple JupyterBook project rendering that notebook. See what works / what breaks.
- Look at https://github.com/jupyter-book/example-js-anywidget/tree/main which is an example aiming to provide support to `anywidget` based widgets in JupyterBook, also related to https://github.com/jupyter-book/mystmd/issues/2603#issuecomment-3874016260
- See if there's simple config to make `lonboard` work fine in JupyterBook outputs, and create a simple example / demo

We use JupyterBook a fair bit to [publish tutorials](https://developmentseed.org/building_capacity/docs/index.html), etc. Being able to use `lonboard` as part of our JupyterBook outputs would be really nice!

Wanted to create this ticket to not lose track - if someone is able to spend some time trying things out, that's great, else I'll try and make some time soon.

cc-ing a few folks who might be interested in this issue and / or following along - @weiji14 @wildintellect @choldgraf @agoose77 and ofc @kylebarron