[mkdocs] some examples don't run in the docs

If you take an example like this from the current docs, it doesn't run in the mkdocs site

https://plotly.com/javascript/tile-map-layers/#openstreetmap-tiles

This example uses d3 but the mkdocs site isn't loading that. 

We should:

- determine what other JS libraries are needed by the docs and ensure the are loaded 
and/or
- rewrite examples to make sure no additional JS libraries are needed