add docker-compose instructions

docker-compose.yaml

@@ -11,13 +11,25 @@ services:
 
   pgadmin:
     image: dpage/pgadmin4:4
-    ports:
-      - 8090:80
+    labels:
+      - "traefik.http.routers.pgadmin.rule=Host(`pgadmin.localhost`)"
+      - "traefik.http.services.pgadmin-service.loadbalancer.server.port=80"
     volumes:
       - pgadmin:/var/lib/pgadmin
     environment:
       PGADMIN_DEFAULT_EMAIL: postgres
       PGADMIN_DEFAULT_PASSWORD: postgres
+  
+  traefik:
+    image: traefik:v2.2
+    labels:
+      - "traefik.http.routers.traefik.rule=Host(`traefik.localhost`)"
+      - "traefik.http.services.traefik-service.loadbalancer.server.port=8080"
+    command: --api.insecure=true --providers.docker --log.level=ERROR --accesslog=true
+    ports:
+      - "80:80"
+    volumes:
+      - /var/run/docker.sock:/var/run/docker.sock
 
 volumes:
   data: