Delete project files when being used in a parent project

### Description

I would like to see the standalone-project files (`.github`, `.wp-env.json`, `.deployignore`, `.phpcs.xml`, `package.lock.json`, .github (folder), `.phpcs` (folder) etc.) deleted when this project is configured to be rolled up inside a parent project.

### Use Case

When scaffolding in an existing `wp-content` project the standalone project files should be deleted.