Add more Python-related files to gitignore

[Maarrk]

I tend to name all my environments venv, but there's also a bunch of tooling assuming that. Makes the workflow more friendly because you don't see an explosion of files in git.

Based on https://www.toptal.com/developers/gitignore/api/python which is under CC0 license, took a moment to organize the file similarly

Yo dawg, I heard you like venv, so we put more venv in your .gitignore so you can ignore venv while you git

[tetrapod00]

The reasoning makes sense, and it makes sense to cover a wide range of common environment names since the docs are edited by a lot of contributors that we can't enforce a common workflow on.

I don't know enough python to review the details, though. Would appreciate other reviews.

For future reference the CC0 license is specified here (permalink); it's not specified in the linked file in the PR itself. But a gitignore likely falls under fair use anyway?

[Maarrk]

But a gitignore likely falls under fair use anyway?

I am not a lawyer, but these few lines are too trivial to have any discussion of copyright over them.

I only added that remark to show that they aren't my idea but come from a widely used source, to make it easier to trust for maintainers. Here is the same content under the same license from GitHub itself:

https://github.com/github/gitignore/blob/297239c101dcfdfae7e75757ed17ed993df0b4eb/Python.gitignore#L130-L137