How to use silverstripe-image-click-spots?

Question

I am trying to get https://github.com/sunnysideup/silverstripe-image-click-spots to work.

After adding some lines (use ...) and correcting the classes (some left - outs and typos) I can't find out how to use the module.

Unfortunately, the image-click-spots.yml.example is missing on GitHub and the docs are very poor.

All I see is:

MyDataObject:
  extensions:
    - Sunnysideup\ImageClickSpots\Extension\ImageClickSpotsExtension

Can you please provide a basic working example of using this module?