update readme

README.md

@@ -1,2 +1,50 @@
 # drlp
-Short for Direct-RLP: An in-place RLP encoder
+
+[![Build Status](https://github.com/qianbin/drlp/workflows/Go/badge.svg)](https://github.com/qianbin/drlp/actions)
+[![GoDoc](https://godoc.org/github.com/qianbin/drlp?status.svg)](http://godoc.org/github.com/qianbin/drlp)
+[![Go Report](https://goreportcard.com/badge/github.com/qianbin/drlp)](https://goreportcard.com/report/github.com/qianbin/drlp)
+
+Short for Direct-RLP: A fast in-place RLP encoder
+
+
+### Installation
+
+It requires Go 1.19 or newer.
+
+```bash
+go get github.com/qianbin/drlp
+```
+
+### Usage
+
+Number and string 
+```go
+var buf drlp.Buffer
+
+buf.PutUint(10)
+buf.PutString([]byte("hello drlp"))
+
+fmt.Printf("%x\n", buf)
+// 0a8a68656c6c6f2064726c70
+```
+
+List
+```go
+var buf drlp.Buffer
+
+buf.PutString([]byte("this is a list"))
+
+li := buf.List()
+buf.PutString([]byte("lis content"))
+encodedList := li.End()
+
+fmt.Printf("%x\n", encodedList)
+// cc8b6c697320636f6e74656e74
+fmt.Printf("%x\n", buf)
+// 8e746869732069732061206c697374cc8b6c697320636f6e74656e74
+```
+
+## License
+
+The MIT License
+