:meta private: tag does not work

[cysabi]

Some of my docstrings include the :meta private: attribute.

When I build the html files from source, the proper methods are hidden.

However, when using the action, the attribute is not used and even shows up in the documentation:

[ammaraskar]

Hey Lepto, it looks like :meta private: was introduced in Sphinx 3.0+ which is why this doesn't work right now. I'm looking into allowing users to customize their sphinx version in #25, so I'm gonna close this as a duplicate of that.