* creating vignettes ... ERROR

--- re-building 'dataRetrieval.Rmd' using rmarkdown

Warning in engine$weave(file, quiet = quiet, encoding = enc) :

  The vignette engine knitr::rmarkdown is not available because the rmarkdown package is not available. Did you forget to add it to Suggests in DESCRIPTION? Please see https://github.com/yihui/knitr/issues/1864 for more information.

Loading required namespace: sf

--- finished re-building 'dataRetrieval.Rmd'

Preparing for pull request.
Added vignette, nldi functions, and test

Fixes #476