Replace code smell with code weeds

[professor]

In the docs folder, we discuss why we prefer code weeds over code smells. This makes that change front and center in the presentation

[benchristel]

Sorry I just saw this—I apparently wasn't subscribed to notifications on this repo!

If we're going all-in on the rename, then I think there are some other places that would need to change. E.g. the docs/smells directory. I wonder if there's net value in introducing a new metaphor if we still have to explain the old one (which I agree we should, since "code smells" is the commonly used term).