traumar 1.2.6

• Deprecate the n_decimal argument for pretty_number(), use digits
  instead. This is a full deprecation which will now produce an error.
• Remove limits on pretty_percent() so that it can handle negative numbers as
  well as positive. Removed limits bounding the input at [0, 1].
• Added tests for validate_set(), validate_numeric() tests were improved,
  validate_names(), added tests for validate_length() and
  validate_error_type().
• Removed documentation for the validate_*() family of functions and used
  keyword internal in their documentation.
• Implemented usethis::use_tidy_* package helpers to clean up various parts of
  the package such as workflows and using Air as the code formatter
  throughout.