add watchtower to docker-compose and .env and gitea actions

docker-compose.yml

@@ -1,8 +1,13 @@
 services:
   app:
-    build: .
+    image: ${DOCKERHUB_USERNAME}/calendarreminder-app:latest
     ports:
       - "8080:8080"
+    depends_on:
+      db:
+        condition: service_healthy
+    labels:
+      - "com.centurylinklabs.watchtower.enable=true"
     environment:
       - ASPNETCORE_ENVIRONMENT=Production
       - ConnectionStrings__Default=Server=${DB_SERVER};Port=${DB_PORT};Database=${DB_NAME};User=${DB_USER};Password=${DB_PASSWORD};
@@ -32,3 +37,16 @@ services:
       timeout: 5s
       retries: 5
     restart: unless-stopped
+
+  watchtower:
+    image: containrrr/watchtower
+    ports:
+      - "8085:8080"
+    volumes:
+      - /var/run/docker.sock:/var/run/docker.sock
+    environment:
+      - WATCHTOWER_LABEL_ENABLE=true
+      - WATCHTOWER_CLEANUP=true
+      - WATCHTOWER_HTTP_API_UPDATE=true
+      - WATCHTOWER_HTTP_API_TOKEN=${WATCHTOWER_TOKEN}
+    restart: unless-stopped