* add example docker override (one which would disable the mail container)
* move some config options from docker-compose into the default conf
* add missing depends_on
update Dockerfiles/Makefile for use with kopano supported build
introduce a local ldap image with some demo users
include caddy for reverse proxying
add proper documentation and remove obsolete build and push scripts
Signed-off-by: Felix Bartels <felix@host-consultants.de>
