It is a private API which is not critical for our application.
It shortly highlights blocks that are editable after a click in the parent.
As it is not critical and is private, it is a risk, and we should rather not use it.
[MAILPOET-6319]
This approach is used in the Gutenberg repository.
Our original approach, where we imported styles in index files in subdirectories, was a bit fragile
because such a file might be skipped in case a component is imported directly.
[MAILPOET-6320]
