/// Returns the whether `$value` is strictly equal to `true` or the string
/// equivalent of `'true'`.
///
/// In Sass, all values other than `false` and `null` are considered truthy.
/// Sometimes, you may just want to test only for either the Bool type `true` or
/// the String equivalent of `'true'`.
///
/// @param {*} $value - A value to check.
///
/// @return {Bool} Returns `true` if `$value` is `true` or `'true'`.
///
/// @access public
/// @group Utilities
@function equals-true($value) {
  @return not not ($value == true or $value == 'true');
}