The updated installation documentation misses the archive installation instructions
The older documentation referred:
A. Extract archive (tar/zip) from the relevant address listed in the table above.
Extract the eZ distribution archive to a directory, then execute post-install scripts:
The post-install scripts will ask you to fill in some settings, including database settings.
$ cd /<directory>/
$ curl -sS https://getcomposer.org/installer | php
$ php -d memory_limit=-1 composer.phar run-script post-install-cmd
The updated one doesn't refer these instructions.