As a developer I would like CEA installation to upgrade my project

[thescientist13]

Type of Change

• New Feature Request
• Documentation
• Improvement / Suggestion
• Bug
• Other (please clarify below)

Summary

It would be cool if by running npx create-evergreen-app my-app and my-app already exists, it would be great if all the project configuration could be merged / updated in place, e.g.

• webpack
• babel config
• eslintrc

Details

The idea would be try and preserve existing values if possible, and try and upgrade in place (like the Angular CLI or CRA would do)