fix(docs): update expected code

[gforcada]

The example on Generative section names was not the one would expect.

Probably some leftover from a previous refactoring? 🤔

• ran the linter to address style issues (tox -e fix)
• wrote descriptive pull request text
• ensured there are test(s) validating the fix
• added news fragment in docs/changelog folder
• updated/extended the documentation

[gforcada]

I see the filename is wrong and that makes CI failing, which filename should I give it? Do I need to create an issue, or reusing the one from this PR is enough?

[gaborbernat]

You can reuse the one from the PR.