R: Vignettes and other documentation

# Vignettes and other documentation

## Vignettes from package 'groupdata2'

groupdata2::automatic_groups_with_groupdata2 |  | Automatic groups with groupdata2 | HTML | source | R code
groupdata2::cross-validation_with_groupdata2 |  | Cross-validation with groupdata2 | HTML | source | R code
groupdata2::description_of_groupdata2 |  | Description of groupdata2 | HTML | source | R code
groupdata2::introduction_to_groupdata2 |  | Introduction to groupdata2 | HTML | source | R code
groupdata2::time_series_with_groupdata2 |  | Time series with groupdata2 | HTML | source | R code