Update Docker configuration: change command to use entrypoint script, set superuser environment variables, and adjust NGINX settings for port and server name.

app/entrypoint.sh

@@ -0,0 +1,9 @@
+#!/bin/sh
+set -eu
+
+python manage.py migrate --noinput
+python manage.py ensure_admin
+
+exec gunicorn keywarden.wsgi:application --bind 0.0.0.0:80 --workers 3
+
+