adding docker compose file

extending instructions to run docker in README

README.md

@@ -35,3 +35,66 @@ The app will run continuously and send notifications at the scheduled times.
 
 - Python 3.6+
 - Discord webhook URL
+
+## Docker
+
+Build the Docker image from the provided `Dockerfile`:
+
+```bash
+docker build -t thc-webhook .
+```
+
+Run the container (pass your webhook URL via environment variable):
+
+```bash
+docker run -d \
+  --name thc-webhook-app \
+  -e DISCORD_WEBHOOK_URL="https://discord.com/api/webhooks/your_webhook_id/your_webhook_token" \
+  thc-webhook
+```
+
+View logs:
+
+```bash
+docker logs -f thc-webhook-app
+```
+
+Stop and remove the container:
+
+```bash
+docker stop thc-webhook-app && docker rm thc-webhook-app
+```
+
+### Run with Docker Compose (recommended)
+
+A `docker-compose.yml` is included for easy deployment. It reads `DISCORD_WEBHOOK_URL` from the environment. Create a `.env` next to the `docker-compose.yml` with your webhook URL or export the variable in your shell.
+
+Example `.env`:
+
+```text
+DISCORD_WEBHOOK_URL=https://discord.com/api/webhooks/your_webhook_id/your_webhook_token
+```
+
+Start the service:
+
+```bash
+docker compose up -d
+```
+
+Check service logs:
+
+```bash
+docker compose logs -f
+```
+
+Stop the service:
+
+```bash
+docker compose down
+```
+
+### Notes
+
+- For production, prefer passing the webhook URL via a secret manager or Docker secrets rather than committing it to `.env`.
+- The container runs the app as a non-root user for improved security.
+- Use your system's Docker service (Docker Desktop, Docker Engine) to manage images and containers.