Secondary description lines are not being picked up by the `README.md` regeneration

[schlessera]

As an example, the changes in wp-cli/entity-command#213 are not being added to the README.md file when regenerating it.

[ernilambar]

Is this still valid? I am seeing that extra content in the readme file. https://github.com/wp-cli/entity-command?tab=readme-ov-file#wp-post-list