static flush function

[bnomei]

could add static flush function

class time {
    public static function cache($filename, $callback, $expires = null) {
        $TimeCache = new TimeCache();
        return $TimeCache->get($filename, $callback, $expires);
    }
    public static function flush() {
        $dir = c::get('time.cache.path', kirby()->roots()->site() . '/cache-time');
        dir::remove($dir, true); // flush => https://getkirby.com/docs/toolkit/api/dir/remove
    }
}