simple geojson examples

[chriddyp]

we have many great choropleth examples, but not many simple geojson shape examples. That is, using GeoJSON just to highlight regions or zones but not tying it to data.

There are a set of simple GeoJSON shapes here that would be nice to make into simple python examples: https://github.com/plotly/dash/issues/28#issuecomment-310500737

[chriddyp]

Here's an example from the community forum, for example, that was challenging to answer with our current documentation: https://community.plot.ly/t/add-geographic-information-on-dash-maps/28316