Add arxiv template

[alexpghayes]

Would be nice to be able to use the standard pre-print arvix template from overleaf with R markdown

[yihui]

Thanks for the request! Most templates in this package are contributed by users, so either you or someone else has to do the work and send a pull request.

[github-actions]

This old thread has been automatically locked. If you think you have found something related to this, please open a new issue by following the issue guide (https://yihui.org/issue/), and link to this old issue if necessary.