Add optional generation of README.md file in module

[makzef]

Is your feature request related to a problem? Please describe.

We need to add generation of README.md file in module. We want to make it optional.

Describe the solution you'd like (*)

Add a checkbox into the new magento 2 module dialog:

Additional context

Mainline branch: 4.4.0-develop

[makzef]

@magento I am working on this