Port eloquenza's changes

[koppor]

I found @eloquenza's fork using https://useful-forks.github.io/?repo=latextemplates%2FLNCS and found interesting commits. This cherry-picks these changes by @eloquenza to here. I could not use all changes. Following are not ported:

• *.pdf not ignored, because I create figures for LaTeX in the pdf format (to have scalable images)
• Changes in README.md have to go into https://github.com/latextemplates/generator-latex-template/blob/main/generators/app/templates/README.en.md.
• Split configurations is a huger todo for the template generator, thus I created https://github.com/latextemplates/generator-latex-template/issues/53

I finally did git merge -s ours eloquenza/master to have the fork.

Next steps port the updates back to the generator: https://github.com/latextemplates/generator-latex-template/issues/54

[eloquenza]

Thanks for considering my changes!