add language navigator and fix some styles

exampleSite/content/instruction.md

@@ -1,5 +1,5 @@
 ---
-author: Hugo Authors
+author: Mivinci
 title: Instruction
 date: 2021-07-19T10:52:59+08:00
 description: A Clean and minimal Hugo theme porting from the [Hexo Minima](https://github.com/adisaktijrs/hexo-theme-minima). [Click me](https://h.xjj.pub/) to take a look.

exampleSite/content/instruction.zh.md

@@ -0,0 +1,10 @@
+---
+author: Hugo Authors
+title: 使用说明
+date: 2021-07-19T10:52:59+08:00
+description: 
+math: true
+comment: true
+---
+
+你好