A new automatic config update system has been implemented: thanks to the neo config-version field in config.yml file, the plugin will automatically update your config (maintaining all of your settings) when a new config version is released.
The playtimegroup add subcommand has been renamed to "set" to better reflect its functionality. It now adds a new group or overwrites an existing one.
Groups data has been moved from config.yml to DB. The automatic config update will take care of the migration if necessary.