Add example and sections to Block API documentation

To avoid an additional cspell word to keep track I think we should replace examplemodule with just example or module.

Example seems correct to me.

I opened 📌 Remove reference to \Drupal\Core\Block\Annotation\Block (possibly more?) Active for the annotation removal. I left an open question on that ticket about scope range.

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.

Restoring previous status before the bot.

nod_ → closed merge request !8593

Committed c9db648 and pushed to 11.x. Thanks!

Automatically closed - issue fixed for 2 weeks with no activity.