Table of Content not working #52

The command line parameter for table of content is created as --toc.
According to the wkhtmltopdf dokumentation it should be created as toc.

Table Of Contents:
A table of contents can be added to the document by adding a toc object to the
command line. For example:

wkhtmltopdf toc https://doc.qt.io/archives/qt-4.8/qstring.html qstring.pdf