Added DOMAIN environment variable also to vaultwarden, otherwise attachments don't work in some cases.

Using-Docker-Compose.md

@@ -18,6 +18,7 @@ services:
     restart: always
     environment:
       WEBSOCKET_ENABLED: "true"  # Enable WebSocket notifications.
+      DOMAIN: "https://vaultwarden.example.com"  # Your domain; vaultwarden needs to know it's https to work properly with attachments
     volumes:
       - ./vw-data:/data
 
@@ -98,6 +99,7 @@ services:
     restart: always
     environment:
       WEBSOCKET_ENABLED: "true"  # Enable WebSocket notifications.
+      DOMAIN: "https://vaultwarden.example.com"  # Your domain; vaultwarden needs to know it's https to work properly with attachments
     volumes:
       - ./vw-data:/data