update contributing.asc

Author: ousugo

book/05-distributed-git/sections/contributing.asc

@@ -150,10 +150,10 @@ To jessica@githost:simplegit.git
    1edee6b..fbff5bc  master -> master
 ----
 
-The last line of the output above shows a useful return message from the push operation.
-The basic format is `<oldref>..<newref> fromref -> toref`, where `oldref` means the old reference, `newref` means the new reference, `fromref` is the name of the local reference being pushed, and `toref` is the name of the remote reference being updated.
-You'll see similar output like this below in the discussions, so having a basic idea of the meaning will help in understanding the various states of the repositories.
-More details are available in the documentation for https://git-scm.com/docs/git-push[git-push].
+上方输出信息中最后一行显示的是推送操作执行完毕后返回的一条很有用的消息。
+消息的基本格式是`<oldref>..<newref> fromref -> toref`，`oldref`的含义是推送前所指向的引用，`newref`的含义是推送后所指向的引用，`fromref`是将要被推送的本地引用的名字，`toref`是将要被更新的远程引用的名字。
+在后面的讨论中你还会看到类似的输出消息，所以对这条消息的含义有一些基础的了解将会帮助你理解仓库的诸多状态。
+想要了解更多细节请访问文档 https://git-scm.com/docs/git-push[git-push] 。
 
 John 稍候也做了些改动，将它们提交到了本地仓库中，然后试着将它们推送到同一个服务器：