Images were extracted form the PDF provided by Wouter with the command
pdfimages -png -j wouter260316v4.pdf wouter/v4
As usual, I have added the images separately, into the Website-repository,
in order to save storage space in the main Lumiera repo (since storage in
a Git-repository is permanent and can not be shrinked later without
rewriting the history)
Furthermore, I have changed the naming scheme of the images,
adding a prefix with the version number where some image was added.