📝 Refactor README into separate README.md files for backend, frontend, deployment, development (#639)

deployment.md

@@ -0,0 +1,25 @@
+# FastAPI Project - Deployment
+
+You can deploy the using Docker Compose with a main Traefik proxy outside handling communication to the outside world and HTTPS certificates.
+
+And you can use CI (continuous integration) systems to do it automatically.
+
+But you have to configure a couple things first.
+
+## Traefik network
+
+This stack expects the public Traefik network to be named `traefik-public`.
+
+If you need to use a different Traefik public network name, update it in the `docker-compose.yml` files, in the section:
+
+```YAML
+networks:
+  traefik-public:
+    external: true
+```
+
+Change `traefik-public` to the name of the used Traefik network. And then update it in the file `.env`:
+
+```bash
+TRAEFIK_PUBLIC_NETWORK=traefik-public
+```