Document how to add a new C extension module

[tiran]

memo to me

Python 3.12 will drop setup.py. 3.11 has already detects most modules on configure and builds them through Modules/Setup.stdlib. The new system is not well documented yet.

configure.ac

• PY_STDLIB_MOD / PY_STDLIB_MOD_SIMPLE
• SRCDIRS if module is in a subdirectory
• How to write PKG_CHECK_MODULES block

Modules/Setup.stdlib.in

• @MODULE_SPAM_TRUE@spam spam.c egg.c

Makefile.pre.in

• MODULE_SPAM_DEPS=$(srcdir)/Modules/spam.h

[abdnafees]

@tiran Has this issue been resolved?