Also I am not sure what to do with png images in doc-src/Images directory.
There are svg files as well, but I haven't managed to correctly
convert the svg files to png.
It would be great if you would give me ideas or examples.
I'm not sure what upstream is intending with these files but I would
trust that the install mechanism does reasonable things. When starting
the program at least the help menu displays an image. There are several
different image sizes under
/usr/share/icons/hicolor
which are used by various desktop systems (which I not use).
Kind regards
Andreas.