Feature Request: Environment Variable Support in cookiecutter.json

[sandrospadaro]

Adding environment variable support within cookiecutter.json could greatly increase Cookiecutter's adaptability for dynamic configurations.

Example Use Case: Automatically including the developer's name or email in the project metadata without manual updates:

{
  "author_name": "{{ cookiecutter.env('USER', 'Default Name') }}",
  "author_email": "{{ cookiecutter.env('MAILTO', 'default@email.com') }}"
}

This feature would allow developers to create more personalized and context-aware templates effortlessly, enhancing productivity.

Thank you for considering this suggestion.