Update docs for update_all changes

[iliketocode2]

Documentation updates for the associated PR in pyscript.

• Note that these introduce the replacement of className with classes for the update_all function.
• Usage:

# Bulk update all elements.
items.update_all(
    innerHTML="Hello",
    classes="updated-item",
    style={"color": "blue"},
)

[WebReflection]

thanks, and let's wait for the PR to pass CI and be merged, we're also very close to a release so this is just about the perfect timing for this 🙏

[ntoll]

OK. I believe this section of the docs also needs updating: https://docs.pyscript.net/2026.2.1/user-guide/dom/#working-with-collections

You'll need to update this file: https://github.com/pyscript/docs/blob/main/docs/user-guide/dom.md

👍

[iliketocode2]

Thanks for the catch! I'll get on that today 💻

[iliketocode2]

@ntoll I believe all of the necessary changes were made but let me know if I should add a comment indicating the underlying change of update_all's function or anything else. Thanks!