build-articles.md
In pkgdown: Make Static HTML Documentation for a Package

warns about missing images

Code
  build_articles(pkg)
Output
  -- Building articles -----------------------------------------------------------
  Writing 'articles/index.html'
  Reading 'vignettes/html-vignette.Rmd'
  Writing 'articles/html-vignette.html'
Condition
  Warning:
  Missing images in 'vignettes/html-vignette.Rmd': 'foo.png'
  i pkgdown can only use images in 'man/figures' and 'vignettes'