Text wrapping can mess up latex templaes

The (new?) default pandoc behaviour of wrapping long lines can cause issues in templates if there are comments.

For example, if the template has something like this

% \title{$title$}

and if title is long enough to reach the line-wrap character length, then this gets interpolated into something like

% \title{This is a very long title that pandoc will 
wrap into a new line}

This can create all sorts of errors that are very hard to debug. I encountered this issue during a tutorial on creating LaTeX templates and a student was trying different things and commenting out some of them.

Auto wrap also caused issues in bookdown and distill and was solved by adding --wrap=preserve to pandoc arguments.

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Start by locating where rticles builds Pandoc arguments for LaTeX templates, then reproduce the issue with a long interpolated title inside a commented template line. Compare the generated output with Pandoc wrapping preserved; done means interpolation no longer splits commented LaTeX lines and the relevant checks pass.