Automatic creation of a PDF file name when the PDF name isn't transmitted.

[gilardh]

Automatic creation of a PDF file name when the pdf name is not transmitted in the command line.
The name of the PDF in the command line would become optional.
The name of the PDF file could be the date and time of generation.

Example :
use chrono::{DateTime, Local};
let now: DateTime = Local::now();
filename = now.format("%Y-%m-%dT%H:%M:%S").to_string();

[leto]

@gilardh seems like a good feature 👍