message: Sync README.
diff: @@ -59,35 +59,35 @@ echo 'use ' . (microtime(true) - $s) . ' s';
  ```php
  function tcp_pack(string $data): string
  {
  - return pack('n', strlen($data)) . $data;
  + return pack('N', strlen($data)) . $data;
  }
  function tcp_unpack(string $data): string
  {
  - return substr($data, 2, unpack('n', substr($data, 0, 2))[1]);
  + return substr($data, 4, unpack('N', substr($data, 0, 4))[1]);
  }
  $tcp_options = [
  'open_length_check' => true,
  - 'package_length_type' => 'n',
  + 'package_length_type' => 'N',
  'package_length_offset' => 0,
  - 'package_body_offset' => 2
  + 'package_body_offset' => 4
  ];
  ```
  ```php
  -$server = new swoole_websocket_server('127.0.0.1', 9501, SWOOLE_BASE);
  +$server = new Swoole\WebSocket\Server('127.0.0.1', 9501, SWOOLE_BASE);
  $server->set(['open_http2_protocol' => true]);
  // http && http2
  -$server->on('request', function (swoole_http_request $request, swoole_http_response $response) {
  +$server->on('request', function (Swoole\Http\Request $request, Swoole\Http\Response $response) {
  $response->end('Hello ' . $request->rawcontent());
  });
  // websocket
  -$server->on('message', function (swoole_websocket_server $server, swoole_websocket_frame $frame) {
  +$server->on('message', function (Swoole\WebSocket\Server $server, Swoole\WebSocket\Frame $frame) {
  $server->push($frame->fd, 'Hello ' . $frame->data);
  });
  // tcp
  $tcp_server = $server->listen('127.0.0.1', 9502, SWOOLE_TCP);
  $tcp_server->set($tcp_options);
  -$tcp_server->on('receive', function (swoole_server $server, int $fd, int $reactor_id, string $data) {
  +$tcp_server->on('receive', function (Swoole\Server $server, int $fd, int $reactor_id, string $data) {
  $server->send($fd, tcp_pack('Hello ' . tcp_unpack($data)));
  });
  $server->start();
  