Discuss adding `:meta private:` to the doc string

[bearomorphism]

We probably can try something like adding :meta private: to the doc string instead. Even though it's a sphinx thing, I think this should be sufficient

Originally posted by @Lee-W in https://github.com/commitizen-tools/commitizen/pull/1466#discussion_r2126744457

[Lee-W]

it's more like choose between _func_name and :meta private:. We use both in Airflow. But Airflow uses Sphinx. can discuss a bit on what we want

[Lee-W]

relates to https://github.com/commitizen-tools/commitizen/issues/1446