updated README with mysqldump commands
updated README with mysqldump commands

xiongjungit/mysql,westhouseproject/docker-mysql,pchico83/mysql,jechiy/mysql,hasufell/docker-gentoo-mysql,tutumcloud/tutum-docker-mysql,pitrho/docker-mysql,alexmcroberts/mysql,drasamsetti/mysql,mrojass/mysql,jarekkozak/mysql,tutumcloud/mysql,wahyutaufik/mysql,ball6847/mysql,jwjohns/tutum-docker-mysql,lucienh/mysql,Carrotzpc/mysql