Add notes about ownership glitches + using prebuilt

docker-compose.yaml

@@ -1,6 +1,8 @@
 services:
   remoteterm:
     build: .
+    # Optional on Linux: run container as your host user to avoid root-owned files in ./data
+    # user: "${UID:-1000}:${GID:-1000}"
     ports:
       - "8000:8000"
     volumes:
@@ -26,4 +28,3 @@ services:
     # devices:
     #   - /dev/ttyUSB0:/dev/ttyUSB0
     restart: unless-stopped
-