cli: create new file

Basically, I just want the file to be saved at the current location and opened in inkscape.

If I navigate to a directory via the command line, I can just launch `inkscape -cn new-file-name.svg`, to create a file that I can start editing in inkscape, and when I press Ctrl+S, the file is saved in the current directory where inkscape was launched from, instead of having to click through the save menu to find this directory again.

Here -cn is the option to create a new file.