fix: resolve message sending failure when containing "\n" using webhook and custom channel (#111)

* 使用webhook和custom通道发送消息时如果内容中包含\n会推送失败的问题

* 消息查看页面增加markdown内容解析，访问链接页面增加GFM拓展解析

* 访问链接页面GFM footnote支持

web/src/components/MessagesTable.js

@@ -5,6 +5,7 @@ import { API, openPage, showError, showSuccess, showWarning } from '../helpers';
 import { ITEMS_PER_PAGE } from '../constants';
 import { renderTimestamp } from '../helpers/render';
 import { Link } from 'react-router-dom';
+import { marked } from 'marked';
 
 function renderStatus(status) {
   switch (status) {
@@ -416,7 +417,7 @@ const MessagesTable = () => {
           ) : (
             ''
           )}
-          {message.content ? <p>{message.content}</p> : ''}
+          {message.content ? <div dangerouslySetInnerHTML={{ __html: marked.parse(message.content) }}></div> : ''}
         </Modal.Content>
         <Modal.Actions>
           <Button