Add underlined doc for bot.sendMessage
@@ -1303,6 +1303,7 @@ bot.sendMessage("383003333751856129","Hello You :)")
- message (str)
* \*\*bold\*\*
* \*italicized\*
+ * \_\_underlined\_\_
* \~\~strikethrough\~\~
* \>quoted
* \`code\`
