Fix issue#20, format following the guidelines

SUMMARY.md

@@ -1,9 +1,9 @@
 # Summary
 
 * [前言](README.md)
-* [Docker简介](introduction/README.md)
-   * [什么是Docker](introduction/what.md)
-   * [为什么要用Docker](introduction/why.md)
+* [Docker 简介](introduction/README.md)
+   * [什么是 Docker](introduction/what.md)
+   * [为什么要用 Docker](introduction/why.md)
 * [基本概念](basic_concept/README.md)
    * [镜像](basic_concept/internal.md)
    * [容器](basic_concept/container.md)
@@ -38,17 +38,17 @@
    * [容器互联](network/linking.md)
 * [高级网络配置](advanced_network/README.md)
    * [快速配置指南](advanced_network/quick_guide.md)
-   * [配置DNS](advanced_network/dns.md)
+   * [配置 DNS](advanced_network/dns.md)
    * [容器访问控制](advanced_network/access_control.md)
    * [端口映射实现](advanced_network/port_mapping.md)
-   * [配置docker0](advanced_network/docker0.md)
+   * [配置 docker0 网桥](advanced_network/docker0.md)
    * [自定义网桥](advanced_network/bridge.md)
    * [工具和示例](advanced_network/example.md)
    * [编辑网络配置文件](advanced_network/config_file.md)
    * [实例：创建一个点到点连接](advanced_network/ptp.md)
 * [实战案例](cases/README.md)
-   * [使用 Supervisor来管理进程](cases/supervisor.md)
-   * [创建tomcat/weblogic集群](cases/tomcat.md)
+   * [使用 Supervisor 来管理进程](cases/supervisor.md)
+   * [创建 tomcat/weblogic 集群](cases/tomcat.md)
    * [多台物理主机之间的容器互联](cases/container_connect.md)
    * [标准化开发测试和生产环境](cases/environment.md)
 * [安全](security/README.md)
@@ -66,7 +66,7 @@
    * [基本架构](underly/arch.md)
    * [名字空间](underly/namespace.md)
    * [控制组](underly/cgroups.md)
-   * [Union文件系统](underly/ufs.md)
+   * [Union 文件系统](underly/ufs.md)
    * [容器格式](underly/container_format.md)
    * [网络](underly/network.md)
 * [附录一：命令查询](appendix_command/README.md)