docs: 增加演示站点运行说明并同步英文文档

Author: Ljzd-PRO

README.md

@@ -165,6 +165,22 @@
    poetry run python manage.py runserver
    ```
 
+## 🕹️ 运行演示站点
+
+您也可以切换到 `demo` 分支，运行我们提供的演示站点，查看项目效果，该分支已经构建好了前端资源，且包含样例媒体文件和数据库文件。
+
+（如果无法切换到 `demo` 分支，请确保您已存储当前更改，您可以直接暂时删除自动创建的 `files` 和 `db.sqlite3` 然后重试）
+
+```bash
+git chekout demo
+```
+```bash
+poetry install --no-root
+```
+```bash
+poetry run python manage.py runserver
+```
+
 ## ⚙ 后端配置
 
 可通过编辑 `connectClub/settings.py` 来修改，或设置以 `CONNECT_CLUB_` 开头的环境变量设置部分配置

README_en.md

@@ -161,6 +161,22 @@ Below are screenshots of the application. Click any thumbnail to open the full i
 	 poetry run python manage.py runserver
 	 ```
 
+## 🚀 Run the demo site
+
+You can switch to the `demo` branch to run the provided demo site and see the project in action. This branch already includes built frontend assets and sample media and database files.
+
+(If you cannot switch to the `demo` branch, make sure you have saved your current changes. You can temporarily delete the automatically created `files` directory and `db.sqlite3` then try again.)
+
+```bash
+git checkout demo
+```
+```bash
+poetry install --no-root
+```
+```bash
+poetry run python manage.py runserver
+```
+
 ## ⚙ Backend configuration
 
 You can modify settings in `connectClub/settings.py` or set environment variables prefixed with `CONNECT_CLUB_` for some configuration options.