fix: remove deprecated compose version tag

examples/heimdall/docker-compose.yml

@@ -1,6 +1,5 @@
-version: "3"
-
 services:
+
   heimdall:
     image: linuxserver/heimdall:latest  
     container_name: heimdall
@@ -11,6 +10,8 @@ services:
       - TZ=Europe/Berlin
     ports:
       - 8099:80
+    expose:
+      - 80
     restart: unless-stopped
     volumes:
       - ${DOCKER_VOLUME_STORAGE:-/mnt/docker-volumes}/heimdall:/config