[Catalog-sig] Can PyPI have a new field that stores the code repository URL?

["Martin v. Löwis"]

> In PEP-345 there isn't a specific URL field. Instead we have to hope
> that people add something and then follow a 'source code' label
> convention.
[...]
> My request is for a obvious, specific field.

I don't think these need to contradict each other: it could be a
Project-URL, but still could be an obvious, specific field.
Furthermore, I could envision PyPI setting standard labels.
I wouldn't call it "code repository URL", but "Subversion",
"Mercurial", or "git", with a free-form option of putting in
an arbitrary label.

Regards,
Martin