docs: add missing manual deployment documentation (#7)

* docs: add missing manual deployment documentation

* docs: fix manual deployment steps

* docs: update readme

---------

Co-authored-by: JustSong <songquanpeng@foxmail.com>

README.md

@@ -70,6 +70,14 @@ _✨ All in one 的 OpenAI 接口，整合各种 API 访问方式，开箱即用
 1. 从 [GitHub Releases](https://github.com/songquanpeng/one-api/releases/latest) 下载可执行文件或者从源码编译：
    ```shell
    git clone https://github.com/songquanpeng/one-api.git
+   
+   # 构建前端
+   cd one-api/web
+   npm install
+   npm run build
+
+   # 构建后端
+   cd ..
    go mod download
    go build -ldflags "-s -w" -o one-api
    ````