docs: add permalink zh translation (#954)

Author: suyanhanx

.github/PULL_REQUEST_TEMPLATE.md

@@ -15,7 +15,7 @@
 - [ ] Build-related changes
 - [ ] Other, please describe:
 
-If changing the UI of default theme, please provide the **before/after** screenshot: 
+If changing the UI of default theme, please provide the **before/after** screenshot:
 
 **Does this PR introduce a breaking change?** (check one)
 

packages/docs/docs/zh/guide/permalinks.md

@@ -1,8 +1,9 @@
-# Permalinks
+# 永久链接
 
-## Background
+## 背景
 
-Before 1.x.x, vuepress retrieves all markdown files in the documents source directory and defines the page links based on the file hierarchy. e.g. if you have the following file structure:
+在 1.x.x 版本之前，VuePress 会检索文档源目录下的所有 markdown 文件并按照文件的层次结构去定义页面链接。
+比如你有以下的文件结构：
 
 ```
 ├── package.json
@@ -13,44 +14,36 @@ Before 1.x.x, vuepress retrieves all markdown files in the documents source dire
     └── tags.md
 ```
 
-Then you will get following available pages:
+那么你就会获得以下的可用页面：
 
 ```
 /source/
 /source/tags.html
 /source/_post/intro-vuepress.html
 ```
 
-However, for a blog system, we hope that the link of a post can be customized. VuePress started supporting this feature from `1.0.0`. which is known as `permalink`. Then, the actual pages would be:
+看起来我们已经发现了 blog 的阴暗面。让我们继续看下去。
 
-```
-/source/
-/source/tags/
-/source/2018/4/1/intro-vuepress.html
-```
-
-It seems that we have seen the shadow of the blog. Let's continue to look down.
+## 永久链接
 
-## Permalinks
+一个永久链接是一个旨在未来很多年里维持不变的 URL，由此产生一个发生链接失效（link rot<sup>[1][1]</sup>）的可能性较小的超链接。VuePress 支持一种灵活的方式去生成固定链接，这种方式允许你使用各种模板变量。
 
-A permalink is a URL that is intended to remain unchanged for many years into the future, yielding a hyperlink that is less susceptible to link rot<sup>[1]</sup>. VuePress supports a flexible way to build permalinks, allowing you to leverage various template variables.
+默认的永久链接是`/:regular`。
 
-The default permalink is `/:regular`.
+### 配置永久链接
 
-### Configure Permalinks
-
-You can configure globally to apply it for all pages:
+你可以使用全局配置来向所有页面应用永久链接：
 
 ```js
 // .vuepress/config.js
 module.exports = {
-  permalink: '/:year/:month/:day/:slug'
-}
+  permalink: "/:year/:month/:day/:slug"
+};
 ```
 
-Alternatively, you can also set permalink on a page only, and it will have a higher priority than the global settings.
+另外，你也可以只为单独一个页面去设置永久链接。这种方式比全局配置拥有更高的优先级。
 
-📝 __hello.md__:
+📝 **hello.md**:
 
 ```markdown
 ---
@@ -61,14 +54,17 @@ permalink: /hello-world
 Hello!
 ```
 
-### Template Variables
-
-| Variable | Description |
-|---|---|
-|:year|Published year of posts (4-digit)|
-|:month|Published month of posts (2-digit)|
-|:i_month|Published month of posts (Without leading zeros)|
-|:day|Published day of posts (2-digit)|
-|:i_day|Published day of posts (Without leading zeros)|
-|:slug|Slugified file path (Without extension)|
-|:regular| Permalink generated by VuePress by default, for implementation see [here](https://github.com/vuejs/vuepress/blob/next/packages/%40vuepress/shared-utils/lib/fileToPath.js) |
+### 模板变量
+
+| 变量 | 介绍 |
+| --- | --- |
+|:year|文章发布的年份 (4数字)|
+|:month|文章发布的月份 (2数字)|
+|:i_month|文章发布的月份 (前面不带0)|
+|:day| 文章发布的日份 (2数字)|
+|:i_day|文章发布的日份 (前面不带0)|
+|:slug| 蛞蝓化文件路径 (不带扩展名)|
+|:regular|VuePress默认的生成永久链接的方式，具体实现看 [这里][2]
+
+[1]:https://en.wikipedia.org/wiki/Link_rot
+[2]:https://github.com/vuejs/vuepress/blob/next/packages/%40vuepress/shared-utils/lib/fileToPath.js