Add startup logging via start.sh

Dockerfile

@@ -43,6 +43,6 @@ ENV FLASK_ENV=production \
 
 EXPOSE 7860
 
-CMD ["gunicorn", "--bind", "0.0.0.0:7860", "--workers", "1", \
-     "--timeout", "300", \
-     "app:app"]
+COPY start.sh .
+RUN chmod +x start.sh
+CMD ["./start.sh"]