build: fix docker and add usage in README.md

Dockerfile

@@ -1,5 +1,4 @@
 FROM alpine:3.18.4
-WORKDIR /app
-COPY reaper /app/reaper
+COPY reaper /usr/local/bin/reaper
 
-CMD ["/app/reaper"]
+CMD ["reaper"]

README.md

@@ -7,11 +7,17 @@ REpository ArchivER(REAPER) is a tool to archive repositories from any Git serve
 ## Installation
 
 ```bash
-go install github.com/leslieleung/reaper@latest
+$ go install github.com/leslieleung/reaper@latest
 ```
 
 Or get from [Release](https://github.com/LeslieLeung/reaper/releases).
 
+### docker
+
+```bash
+$ docker run --rm -v $(pwd):/reaper leslieleung/reaper:latest reaper -c config.yaml run
+```
+
 ## Usage
 
 You have to create a configuration file to use REAPER.

README_zh.md

@@ -10,7 +10,13 @@ REpository ArchivER（REAPER）是一个用于从任何Git服务器归档 Git 
 go install github.com/leslieleung/reaper@latest
 ```
 
-或从 [Release](https://github.com/LeslieLeung/reaper/releases) 获取。 
+或从 [Release](https://github.com/LeslieLeung/reaper/releases) 获取。
+
+### docker
+
+```bash
+$ docker run --rm -v $(pwd):/reaper leslieleung/reaper:latest reaper -c config.yaml run
+```
 
 ## 使用方法