Integrate with 'drush generate' command

Problem/Motivation

Make it easier to create a stub script for use with batch operations.

There are already sample scripts that can be copied, but a few of the steps (like putting the stub script in the correct directory and setting the namespace) can be automated.

Proposed resolution

Integrate with the drush generate command.

From drush help generate:

See https://github.com/Chi-teck/drupal-code-generator for a README and bug reports.

I do not see any documentation there, but I think the right way to start is

drush generate drush:generator

How hard can it be? ;)

Remaining tasks

User interface changes

API changes

Data model changes