* add new option for kwmbridge dnat mode
* add local config for test of nat functionality
* use variable instead of real ip
* move turn configuration to the right place
* update kwmbridge
* remove trivy
* sort .gitignore and add apt_auth.conf to it
* add helper to setup.sh to create apt_auth.conf (user still needs to enter their own credentials)
* only create apt_auth.conf in make if it doesn't already exist
* add tooling to core dockerfile and makefile to use build secrets
* add ignore for hadolint as mounting syntax is currently not supported so far
* update to latest docker on travis for buildkit support
* documentation
* sort gitignore
* add dockerfile syntax definition for build args
* fixes for setup-tools.sh
fixes https://github.com/zokradonh/kopano-docker/issues/266
* add startup tests for meet demo
* add architecture to contributing file
* define ical_listen for kopano-ical
* precreate database if it does not yet exist
* fix spelling
* move docker-hub-helper in a general ci folder
* move installation of tools into dedicated script (will make it easier to use a different ci platform)
* mention the setup-tools script in contributing and move testing instructions in there as well