update sample essay and readme

Former-commit-id: ba8c6c5

README.md

@@ -6,6 +6,9 @@
 
 预览（较完整的论文预览见这里: [😀](https://blog.keldos.me/2021/05/md-latex-template/)）：
 
+![sample-essay_1](Supplemental/sample-essay-image/sample-essay_1.jpg)
+![sample-essay_2](Supplemental/sample-essay-image/sample-essay_2.jpg)
+
 | ![image-20210526201241978](https://gitee.com/Keldos-Li/picture/raw/master/img/image-20210526201241978.png) | ![image-20210526201312507](https://gitee.com/Keldos-Li/picture/raw/master/img/image-20210526201312507.png) |
 | ------------------------------------------------------------ | ------------------------------------------------------------ |
 | ![image-20210526201429764](https://gitee.com/Keldos-Li/picture/raw/master/img/image-20210526201429764.png) | ![image-20210526201611922](https://gitee.com/Keldos-Li/picture/raw/master/img/image-20210526201611922.png) |

Supplemental/sample-essay.md

@@ -193,7 +193,7 @@
 
 
 **参考文献:** 
-<div>
+
 ［1］  维基百科编者.操作系统[G/OL].维基百科,2020(2020-11-24) [2021-01-09]. https://zh.wikipedia.org/w/index.php?title=操作系统&oldid=62920825.
 ［2］  计算机操作系统及发展探讨.田舜文[J].数码设计  （下）2020,9(6):3.
 ［3］  计算机操作系统功能与其相关分类.宋辰辉[J].电脑迷,2018(7):15.
@@ -208,5 +208,3 @@
 ［12］ Statcounter. Desktop Operating System Market Share China [DS/OL]. (2020-12-20) [2021-01-09]. https://gs.statcounter.com/os-market-share/desktop/china/
 ［13］ 维基百科编者.Microsoft Windows[G/OL].维基百科, 2021(2021-01-02)[2021-01-10]. https://zh.wikipedia.org/w/index.php?title=Microsoft_Windows&oldid=63546256.
 ［14］ 韩兵,李海坤.浅谈Windows操作系统[J].数码世界,2017(06):66-67.
-</span>
-