Update CIF documentation for recent Inkscape versions

While working on the SBE FIFO example, I noticed that our CIF documentation regarding Inkscape is outdated in several places. Inkscape 1.0 and higher for instance no longer use the bottom left corner of the canvas as the origin, but use (by default) the upper left corner, just like SVG itself. There are more changes, for instance to the UI of Inkscape. We should update the CIF documentation to reflect current versions of Inkscape.