Set write permissions for group after initial composer command

customer/bison/core#13 Move the optional init file to the web directory before calling drush site:init

Implement new option to clean up containers after the event

Move the optional .init_site.json to /tmp/init_site.json in order to keep it available even after truncating current directory

customer/bison/core#3 Improve automation such that L3D does all the initial site setup if the required parameters are available