docs: update

README.md

@@ -3,4 +3,43 @@
 ![Go](https://github.com/geekdada/flomo-cli/workflows/Go/badge.svg)
 [![codecov](https://codecov.io/gh/geekdada/flomo-cli/branch/master/graph/badge.svg?token=FJ3Y2ZB8YS)](https://codecov.io/gh/geekdada/flomo-cli)
 
-A CLI tool for flomo.
+A CLI tool for [flomo](https://flomoapp.com/register2/?Mzk3).
+
+## 安装
+
+在 [Releases](https://github.com/geekdada/flomo-cli/releases) 页面下载对应的二进制文件。
+
+## 使用
+
+### 添加一条新的墨
+
+```bash
+$ flomo new --api <YOUR API> "一条新的墨"
+```
+
+### 添加一条带标签的墨
+
+```bash
+$ flomo new --api <YOUR API> --tag "随手记" "一条新的墨"
+```
+
+**效果**
+
+![CleanShot 2020-12-24 at 20.27.55@2x.png](https://i.loli.net/2020/12/24/g3v7c6fwOKyauRT.png)
+
+### 使用环境变量来指定 API
+
+```bash
+$ export FLOMO_API=<YOUR API>
+$ flomo new --tag "随手记" "一条新的墨"
+```
+
+### 将文本文件添加到浮墨
+
+```bash
+$ cat memo.txt | flomo new --tag "Quote"
+```
+
+## LICENCE
+
+[MIT](./LICENSE)