add watchtower

Signed-off-by: Amelia Aronsohn <squirrel@wearing.black>

docker-compose.yml

@@ -1,3 +1,4 @@
+---
 networks:
   backend:
     external: false
@@ -5,6 +6,7 @@ networks:
 volumes:
   gitea-data:
 
+
 services:
   gitea:
     image: gitea/gitea:1
@@ -17,3 +19,11 @@ services:
     ports:
       - "2222:22"
       - "127.0.0.1:3000:3000"
+
+  watchtower:
+    image: containrrr/watchtower
+    volumes:
+      - /var/run/docker.sock:/var/run/docker.sock
+      # - /root/.docker/config.json:/config.json
+      # Once an hour
+    command: --interval 3600