Idea for power users: possibilities to run dev/init non-interactively

[schmengler]

Default values and supported Magento versions could be passed by optional command line options or environment variables, e.g.

dev/init --non-interactive --vendor=integer-net --author-github=schmengler [...]

M2MT_VENDOR=integer-net
M2MT_AUTHOR_GITHUB=schmengler
...
dev/init  --non-interactive

Environment variables would override default values, CLI options would override environment variables.

The --non-interactive flag will use those default values and not ask questions.

For Magento version compatibility, the currently officially supported versions would be assumed.