Check: files in ‘vignettes’, Result: WARNING Files in the 'vignettes' directory but no files in 'inst/doc': ‘introduction.Rmd’ ‘simulation.Rmd’ ‘simulation.bib’ Check: package vignettes, Result: WARNING Directory 'inst/doc' does not exist. Package vignettes without corresponding single PDF/HTML: ‘introduction.Rmd’ ‘simulation.Rmd’