message: Clarify comment on isRuleGroup
diff: import type { RuleType, RuleGroupTypeAny } from '../types';
  /**
  - * Determines if this is a RuleType or RuleGroupType
  + * Determines if this is a RuleGroupType or RuleGroupTypeIC.
  + *
  + * May be removed in a future major version.
  + *
  * @deprecated
  */
  const isRuleGroup = (ruleOrGroup: RuleType | RuleGroupTypeAny): ruleOrGroup is RuleGroupTypeAny => {
  