[Feature request, Jupyter Widget] Export map as image

**Is your feature request related to a problem? Please describe.**
Visualising data at scale may need the creation of videos / pdfs with several visualisations.

**Describe the solution you'd like**
A function .export_to_image that would return / save an image screenshot of the map. Later these images could be used to create reports at scale (e.g. 10-100+ visualisations with different data and/or simply different cities).

**Describe alternatives you've considered**
Not sure how, but theoretically I could access the local html file which is currently generated and take a screenshot.

**Additional context**
na