Extend template for renv packaging

[zuphilip]

A more reproducible approach w.r.t. to packaging is using renv instead of the install.R file. Thus I wonder whether the template could be extended to handle renv packaging as well?

Essentially one could add the following line to the template:

RUN if [ -f renv.lock ]; then R -e "renv::restore()"; fi

However, maybe some further changes might be needed, e.g. not having the files directly in the home directory of the NB_USER but rather in a subdirectory of it. At least that was what I came up after some try-and-error work.

[cboettig]

yes, should be fine in most cases. renv already has detailed docs on a few different ways to do Docker builds with renv, https://rstudio.github.io/renv/articles/docker.html .

This binder recipe is specific to compatibility for mybinder.org (with i.e. python/jupyter + Rstudio), but could probably use a refresh. For instance, in all these cases the user is still responsible for either choosing a base image that has the necessary system libraries or editing apt.txt explicitly. @eddelbuettel et al's work with BSPM is a much simpler, more elegant solution for this in most cases, (though without as strong version promise, though docker image tags provide an alternative mechanism for that.)