performance 0.14.0

Breaking Changes

• The "Increased SE" column in the output of check_collinearity() was renamed
  into "adj. VIF" (=adjusted VIF). Furthermore, the computation of the adjusted
  VIF now correctly accounts for the numbers of levels (i.e. degrees of freedom)
  for factors.

New functions

• New function check_group_variation() to check within-/between-group
  variability (this function will replace check_heterogeneity_bias() in
  future releases.)

• New functions performance_reliability() and performance_dvour(). These
  functions provide information about the reliability of group-level estimates
  (i.e., random effects) in mixed models.

Changes

• Singularity checks with check_singularity() are now more efficient and also
  include the random effects for the dispersion component (from package
  glmmTMB). Furthermore, a check argument allows to check for general
  singularity (for the full model), or can return singularity checks for each
  random effects term separately.

Bug fixes

• Fixed issue with wrong computation of pseudo-R2 for some models where the
  base-model (null model) was updated using the original data, which could
  include missing values. Now the model frame is used, ensuring the correct
  number of observations in the returned base-model, thus calculating the
  correct log-likelihood and returning the correct pseudo-R2.

• Fixed examples in check_outliers().