Since this is a simple documentation fix, I directly filed it as PR instead of creating an issue first.

During my investigation on issues with os.startfile's annotations in typeshed, I discovered that the first argument name differs between documentation and implementation. ( See python/typeshed#10991 )

While the official docs list the argument name as path (docs), the CPython source code has the first argument as filepath (CPython/main), and firing up a REPL to check actual behavior mirrors the same:

>>> from os import startfile
>>> startfile(path='explorer')
Traceback (most recent call last):
  File "<pyshell#1>", line 1, in <module>
    startfile(path='explorer')
TypeError: startfile() missing required argument 'filepath' (pos 1)

This PR aims to align the docs with the implementation by renaming the path argument to filepath.

📚 Documentation preview 📚: https://cpython-previews--112359.org.readthedocs.build/

• Issue: Clarify signature of os.startfile() #114673