Add init/scaffold stage

[gumanista]

Right now we are doing 'silent' project initiation by creating missed files, copying files, etc
It would make sense to have it as a separate task, not running all the times we are running a project. On this stage we can:

• set project variables: theme, name, etc
• set COMPOSE_FILE variable to include necessary docker-compose files (for example os-specific)
• traefik usage
  etc

[andypost]

Good idea to separate init stage butbwe still need some validation before each execution

[gumanista]

Agree, but don't need to take decisions 'silently'. Just provide recommendations. Probably this should be an additional issue.