modify: add docker

docs/usage.md

@@ -4,7 +4,7 @@ TrafficSafeAnalyzer delivers accident analytics and decision support through a S
 
 ## Start the app
 
-1. Activate your virtual or conda environment.
+1. Activate your virtual or conda environment（或在容器中运行，见下）.
 2. From the project root, run:
 
    ```bash
@@ -13,6 +13,8 @@ TrafficSafeAnalyzer delivers accident analytics and decision support through a S
 
 3. Open `http://localhost:8501`. Keep the terminal running while you work in the browser.
 
+> 使用 Docker？运行 `docker build -t trafficsafeanalyzer .` 与 `docker run --rm -p 8501:8501 trafficsafeanalyzer` 后，同样访问 `http://localhost:8501`。
+
 ## Load input data
 
 Use the sidebar form labelled “数据与筛选”.