docs: update README

README.md

@@ -2,8 +2,65 @@
 
 NodeJS client for [SeaweedFS](https://github.com/chrislusf/seaweedfs)
 
-# Quick start
+## Install
 
 ```
 $ npm install @trubavuong/seaweedfs
 ```
+
+## APIs
+
+### BlockStorage
+
+```
+const { BlockStorage } = require('@trubavuong/seaweedfs');
+```
+
+#### Constructor
+
+```
+const blockStorage = new BlockStorage({
+  endpoint: 'http://localhost:9333',
+});
+```
+
+#### blockStorage.reserve({ count })
+
+```
+const { name } = blockStorage.reserve({
+  count: 10,
+});
+```
+
+#### blockStorage.add({ data })
+
+```
+const { name, size } = blockStorage.add({
+  data: fileData,
+});
+```
+
+#### blockStorage.replace({ data, name })
+
+```
+const { name, size } = blockStorage.replace({
+  name: fid,
+  data: fileData,
+});
+```
+
+#### blockStorage.get({ name })
+
+```
+const fileStream = blockStorage.get({
+  name: fid,
+});
+```
+
+#### blockStorage.delete({ name })
+
+```
+const isDeleted = blockStorage.delete({
+  name: fid,
+});
+```