function getRule(ruleId, configArrays) {
	for (const configArray of configArrays) {
		const rule = configArray.pluginRules.get(ruleId);

		if (rule) {
			return rule;
		}
	}
	return builtInRules.get(ruleId) || null;
}
Get a rule.
@param {string} ruleId The rule ID to get.
@param {ConfigArray[]} configArrays The config arrays that have plugin rules.
@returns {Rule|null} The rule or null.