LudvigOlsen/cvms: cvms 1.3.0

In order to reduce dependencies, model coefficients are now tidied with the parameters package instead of broom and broom.mixed. Thanks to @IndrajeetPatil for the contributions.

In cross_validate() and cross_validate_fn(), fold columns can now have a varying number of folds in repeated cross-validation. Struggling to choose a number of folds? Average over multiple settings.

In the Class Level Results in multinomial evaluations, the nested Confusion Matrix and Results tibbles are now named with their class to ease extraction and further work with these tibbles. The Results tibble further gets a Class column. This information might be redundant, but could make life easier.

Adds vignette: Multiple-k: Picking the number of folds for cross-validation.