Update start.sh

I don't think this is a good idea. It will lead to unclean shutdown of the mysql daemon and may lead to data loss.
Suggestion would be to use supervisord like one of those:
http://bixly.com/blog/supervisord-or-how-i-learned-to-stop-worrying-and-um-use-supervisord/
https://gist.github.com/solar/3900946#file-mysqld-ini

Also: If you use the embedded mysql server (I did not plan to do that for myself), the mysql data directory (usually `/var/lib/mysql`) needs to be a volume on the host or Very Bad Things(TM) will happen to users. ;-)
Could you update the README.md accordingly?