Merge pull request #25 from xushiwei/q

small fix

README.md

@@ -8,16 +8,16 @@ github.com/qiniu/x
 [![Coverage Status](https://codecov.io/gh/qiniu/x/branch/master/graph/badge.svg)](https://codecov.io/gh/qiniu/x)
 [![GoDoc](https://img.shields.io/badge/Godoc-reference-blue.svg)](https://godoc.org/github.com/qiniu/x)
 
-# How to build
+## How to build
 
 ```bash
 git clone [email protected]:qiniu/x.git
 cd x
 go install -v ./...
 ```
 
-# Document
+## Document
 
-## Go packages testing utilities
+### Go packages testing utilities
 
 * See [github.com/qiniu/x/ts](https://pkg.go.dev/github.com/qiniu/x/ts?tab=doc)