Here is a simple tutorial of how to screenshot multiple webpage URLs at once!
This one extracts links from webpages : https://addons.mozilla.org/en-US/firefox/addon/link-extractor/
There is also this one : https://addons.mozilla.org/en-US/firefox/addon/link-gopher/
Etc...
Video tutorial... : https://getfireshot.com/demos/capture-website-urls.php
And there you go! It is as simple as that!
Hope this tutorial is of use to someone here! :)