添加coser插件 (#87)

* feat:添加coser

* fix:删除测试代码

* fix:莫名其妙的库

* fix:加个限制器

* fix:修改限制器

* fix:改回去

* fix:改回去

* fix:添加标题

* fix:t大写

* fix:异常注释

* feat:添加文档

* feat:合并消息私聊无效

* feat:改个顺序

* Update go.sum

Co-authored-by: Guohuiyuan <haibaraguo@yeahka.com>
Co-authored-by: 源文雨 <41315874+fumiama@users.noreply.github.com>

README.md

@@ -212,6 +212,8 @@ zerobot -h -t token -u url [-d|w] [-g 监听地址:端口] qq1 qq2 qq3 ...
 - **书评** `import _ "github.com/FloatTech/ZeroBot-Plugin/plugin_book_review"`
     - [x] 书评[关键字]
     - [x] 随机书评
+- **coser** `import _ "github.com/FloatTech/ZeroBot-Plugin/plugin_coser" `
+    - [x] coser
 - **TODO...**
 
 ## 使用方法