ci: publish container image to GHCR

README.md

@@ -41,6 +41,25 @@ npm run lint
 npm run build
 ```
 
+## Container
+
+Run the published image on the default port `5120`:
+
+```bash
+docker run --rm -p 5120:5120 ghcr.io/kr0sh512/pomodoro:latest
+```
+
+Or build it locally:
+
+```bash
+docker build -t pomodoro:local .
+docker run --rm -p 5120:5120 pomodoro:local
+```
+
+GitHub Actions tests the project and publishes multi-architecture images for `linux/amd64` and
+`linux/arm64` to GHCR on pushes to `main` and version tags. Published tags include `latest`,
+`main`, version tags, and `sha-<commit>`.
+
 ## Architecture
 
 - React and TypeScript for the interface and timer state