docs: Update README (#42)

README.md

@@ -1,13 +1,37 @@
-# go-service-dropbox
-
 [![Build Status](https://github.com/beyondstorage/go-service-dropbox/workflows/Unit%20Test/badge.svg?branch=master)](https://github.com/beyondstorage/go-service-dropbox/actions?query=workflow%3A%22Unit+Test%22)
 [![License](https://img.shields.io/badge/license-apache%20v2-blue.svg)](https://github.com/Xuanwo/storage/blob/master/LICENSE)
-[![go storage dev](https://img.shields.io/matrix/go-service-dropbox:aos.dev.svg?server_fqdn=chat.aos.dev&label=%23go-service-dropbox%3Aaos.dev&logo=matrix)](https://matrix.to/#/#go-service-dropbox:aos.dev)
+[![](https://img.shields.io/matrix/beyondstorage@go-storage:matrix.org.svg?logo=matrix)](https://matrix.to/#/#beyondstorage@go-storage:matrix.org)
+
+# go-service-dropbox
 
-dropbox services support for [go-storage](https://github.com/beyondstorage/go-storage)
+[Dropbox](https://www.dropbox.com) service support for [go-storage](https://github.com/beyondstorage/go-storage).
 
 ## Install
 
 ```go
 go get github.com/beyondstorage/go-service-dropbox/v2
 ```
+
+## Usage
+
+```go
+import (
+	"log"
+
+	_ "github.com/beyondstorage/go-service-dropbox/v2"
+	"github.com/beyondstorage/go-storage/v4/services"
+)
+
+func main() {
+	store, err := services.NewStoragerFromString("dropbox:///path/to/workdir?credential=apikey:<apikey>")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// Write data from io.Reader into hello.txt
+	n, err := store.Write("hello.txt", r, length)
+}
+```
+
+- See more examples in [go-storage-example](https://github.com/beyondstorage/go-storage-example).
+- Read [more docs](https://beyondstorage.io/docs/go-storage/services/dropbox) about go-service-dropbox.