Copernicus template update - fixes syntax highlight problem

[RLumSK]

Yet another update for the Copernicus Publication template after the *.tex produced by 'rticles' bounced back from the journal's office telling that additional LaTeX packages and commands are not supported. This was caused by the default syntax highlight enabled in rmarkdown::pdf_document(), which uses additional LaTeX commands.

To ensure that this update aligns with the publisher guidelines, I first discussed with @nuest via email and then contacted the journal's office before making this update (@nuest was in CC).

Hence, this update ensures that the publisher will accept the *.tex produced by the templates without requiring further manual changes by the authors.

More details

• The template now supports the highlight parameter of rmarkdown::pdf_document(). The default is set to NULL, which lets Pandoc set programming code in the verbatim environment. This solution is supported by the publisher, who currently uses the LaTeX packages algorithms and algorithmicx. The author still has the option to use these two LaTeX packages.

• The *.Rmd template and the *.tex template were modified accordingly.

• The options highlights and keep_tex are now explicitly mentioned in the YAML header

• [x] Update Rd and namespace (could be done by devtools::document()).

• [x] Update NEWS.

@nuest, I hope I did everything correctly. However, would you mind looking over it another time?

[RLumSK]

Great and thanks for your support all fine with me!

[cderv]

Thanks for your contribution. Those templates works thanks to you all !