Make the local docs build better reflect real sphinx projects

[javabster]

It has happened a few times now where we can't properly test out CSS fixes locally because we don't have any files that use the typical Sphinx API Reference setup. It would be great if we could add an example API Reference with a dummy Class, with other nested classes and methods.

pages we need:

• top level module page, e.g. https://qiskit.org/documentation/apidoc/circuit.html
• an API Class, e.g. https://qiskit.org/documentation/stubs/qiskit.circuit.ClassicalRegister.html#qiskit.circuit.ClassicalRegister
• a method within a class, e.g. https://qiskit.org/documentation/stubs/qiskit.circuit.Instruction.copy.html#qiskit.circuit.Instruction.copy

[Eric-Arellano]

What remains after https://github.com/Qiskit/qiskit_sphinx_theme/pull/265 is comparing more to https://sphinx-themes.org and making sure that we have everything we want to test.

[javabster]

some things I've noticed would be good to add (edge cases that have caused css issues in the past)

• dispatch functions
• functions that use the typing.overload decorator
• internal reference links in docstrings generally
• examples sections in classes

[Eric-Arellano]

Thanks for the comment, Abby! I added this to the Furo milestone because it will allow us to better verify that we aren't introducing styling regressions for these edge cases when we switch.