added note about selinux and mountpoints
added note about selinux and mountpoints

jaceju/docker-postgresql,timclassic/docker-postgresql,sameersbn/docker-postgresql,zires/docker-postgresql,logandg/docker-postgis,whatever4711/rpi-postgresql,mental-docker/postgresql,crobays/docker-postgresql,boky8/docker-postgresql,markrowsoft/docker-postgres-bdr,bokysan/docker-postgresql,arkkanoid/docker-postgresql,abner/docker-postgresql,Downchuck/docker-postgresql