Argument clinic: outdated tutorial

[eltoder]

Documentation

The tutorial for Argument Clinic in the devguide contains an outdated section. It still describes the early implementation that used to generate calls to PyArg_ParseTuple*() functions. This is no longer the case.

The affected section starts with "First, ensure both places use the same argument-parsing function." and goes for a few paragraphs until "If any of these items differ in any way, adjust your Argument Clinic function specification and rerun Tools/clinic/clinic.py until they are the same."

Given that the output is now very different, this is quite confusing to read. The section probably needs to be completely rewritten.

CC @AlexWaygood @erlend-aasland

[erlend-aasland]

Thanks for the report; do you want to propose a PR?