added docker-compose.yml field on readme.md

README.md

@@ -11,6 +11,13 @@ Services can access the same files via shared volumes and networks
 
 ## ⚡ Startup
 
+Edit `docker-compose.yml` file.
+
+```bash
+environment:
+      - PROXY_PORT=8097 # You can change that if you want.
+```
+
 Run the `start.cmd` file according to your operating system.
 
 ### Windows