Changelog

Improvements

IMPORTANT: MariaDB container now has no volume defined via compose file. The volume is already defined in its Dockerfile, so Docker will create and mount volume automatically. Do not use docker-compose down unless you want to purge your volumes. If you restart docker or use docker-compose stop the volume will persist
Performance improvement for macOS (OSX) users: a new way to sync codebase files is now described. It's based on docker-sync project. Docker is now usable for development on mac. See README.md
New solr container (versions 5.5 and 6.3)
Versions of images, except official, are now frozen. A new version will be released when a newer image version is available
SSHD container is now removed from the standard set
We now have slack where you can any questions about docker4drupal
New documentation http://docs.docker4drupal.org
Instructions updated
License file added (MIT)
Changelog file added

Since MariaDB now uses volume defined in Dockerfile instead of docker-compose, you should export your database and import it again (use mariadb-init volume for this)
Do not use docker-compose down command because it will purge MariaDB volume. Instead use docker-compose stop. If you restart Docker you WILL NOT lose your data