Improve `builtins.__doc__`

[JelleZijlstra]

>>> import builtins
>>> print(builtins.__doc__)
Built-in functions, exceptions, and other objects.

Noteworthy: None is the `nil' object; Ellipsis represents `...' in slices.
>>> 

A few possible improvements:

• None is not actually in the builtins module, as it's a keyword
• Ellipsis has more uses than just slices
• The docstring doesn't explain what "builtins" means. It should say that this module is special in that its namespace is always available, or something along those lines.

Linked PRs

• gh-103886: Improve builtins.__doc__ #104179
• [3.11] gh-103886: Improve builtins.__doc__ (GH-104179) #104257

[tomasr8]

I guess we could reuse (to some degree) the builtins documentation?

[JelleZijlstra]

Much better now, thanks @tomasr8!

[tomasr8]

Thanks for the review!