docs: Update docker documentation to add /sbin/conduwuit to examples

These will likely have to be updated when !1485 goes through.

Fixes: !1529

docs/deploying/docker-compose.for-traefik.yml

@@ -6,6 +6,7 @@ services:
     ### then you are ready to go.
     image: forgejo.ellis.link/continuwuation/continuwuity:latest
     restart: unless-stopped
+    command: /sbin/conduwuit
     volumes:
       - db:/var/lib/continuwuity
       #- ./continuwuity.toml:/etc/continuwuity.toml