Update core.api.php Annotation documentation.

This tries to use replace the use of annotation style in the text and examples with attributes, except for leaving the 'annotations defgroup'. Some parts of the annotations defgroup is copied over to the Plugin API @defgroup and changed as needed to use attributes.

There are still references to annotations that should change.

Is this moving in the right direction?

Not sure how to judge what should remain and what needs to be converted.

I would probably remove the annotation chapter. Or replace it completely with 1-2 sentences that just say that annotation based discovery is deprecated and point to the attribute docs in the plugin component?

Also, the entity type example shouldn't use content_type. The UI refers to node types as content types, so it should be new_entity_type or my_entity_type or something.

#8. Added a sentence at the beginning that it will be deprecated and direct to the plugin section. Since we still need to support annotations I left the remainder of the chapter.

#9: Fixed

I also made more conversions from annotation to attribute in core.api.php and entity.api.php.

I am not sure what the scope is here. The issue title does not match the issue summary. Ideas?

The Needs Review Queue Bot → tested this issue. It fails the Drupal core commit checks. Therefore, this issue status is now "Needs work".

This does not mean that the patch necessarily needs to be re-rolled or the MR rebased. Read the Issue Summary, the issue tags and the latest discussion here to determine what needs to be done.

Consult the Drupal Contributor Guide → to find step-by-step guides for working with issues.

I made the scope 'all *.api.php' files.