/**
 * Generate a random id of designated length
 *
 * @example
 * ```ts
 * randomId(); // -> eg. 'efuc6f1n4xf'
 * randomId(20); // -> eg. '3vsmrbxlh9at0vhcsf1xh'
 * ```
 *
 * @return - A random generated id
 */
export default function randomId(length?: number): string;