fix readme

README.md

@@ -2,6 +2,7 @@
 ![Go](https://github.com/silenceper/wechat/workflows/Go/badge.svg?branch=release-2.0)
 [![Go Report Card](https://goreportcard.com/badge/github.com/silenceper/wechat)](https://goreportcard.com/report/github.com/silenceper/wechat)
 [![godoc](https://img.shields.io/badge/godoc-reference-informational)](https://pkg.go.dev/github.com/silenceper/wechat/v2?tab=doc)
+
 使用Golang开发的微信SDK，简单、易用。