Included user with userid 1000

I included the userid 1000 so files can be modified or deleted from the volumes

\approve @fd

Dockerfile

@@ -35,4 +35,8 @@ RUN pip3 install shapely --upgrade
 
 COPY ./files/start.sh /usr/local/bin
 
+RUN  useradd -r -u 1000 -g appuser
+appuser
+USER appuser
+
 CMD ["/usr/local/bin/start.sh"]