docs: docker compose tip (#296)

* docs: docker compose tip

* chore: update
Co-authored-by: boojack <stevenlgtm@gmail.com>
Co-authored-by: boojack <stevenlgtm@gmail.com>

README.md

@@ -38,6 +38,12 @@ Memos should be running at [http://localhost:5230](http://localhost:5230). If th
 
 See more in the example [`docker-compose.yaml`](./docker-compose.yaml) file.
 
+If you want to upgrade the version of memos, use the following command.
+
+```sh
+docker-compose down && docker-compose build --no-cache && docker-compose up -d
+```
+
 ## Contributing
 
 Contributions are what make the open source community such an amazing place to be learn, inspire, and create. Any contributions you make are greatly appreciated. 🥰