GitLab

* fix #14524 (IndexError when mask prob is too low)

* fix formatting

* correct documentation, add option for setting min_num_masks

* change the semantic meaning of `mask_prob` in _compute_mask_indices

With this commit the meaing of `mask_prob` actually adhered to the probability for each
vector to be the start of a masked span of length.

* fix check_copies test

* fix documentation to semantic meaning of `upper bound of overall masking percentage`, revert changes to _compute_mask_indices

* fix typo