docs: update github actions badge

Signed-off-by: Bo-Yi.Wu <[email protected]>

Author: appleboy

README.md

@@ -1,6 +1,6 @@
 # redis
 
-[![Run Testing](https://github.com/golang-queue/redisdb/actions/workflows/go.yml/badge.svg)](https://github.com/golang-queue/redisdb/actions/workflows/go.yml)
+[![Run Testing](https://github.com/golang-queue/redisdb/actions/workflows/go.yml/badge.svg?branch=main)](https://github.com/golang-queue/redisdb/actions/workflows/go.yml)
 [![codecov](https://codecov.io/gh/golang-queue/redisdb/branch/main/graph/badge.svg?token=FFZN8E2ZZB)](https://codecov.io/gh/golang-queue/redisdb)
 [![Go Report Card](https://goreportcard.com/badge/github.com/golang-queue/redisdb)](https://goreportcard.com/report/github.com/golang-queue/redisdb)