Please add support of thumbnails for SVG files, either by displaying the actual
SVG or by converting it to a raster image. This PHP class is supposed to do the
job:
https://www.phpclasses.org/package/11517-PHP-Parse-and-render-SVG-vectorial-drawing-as-an-image.html
It says that it was created for PHP 5, so it probably needs to be adapted but it
might be a good start.