Interactivity API: Update docs guide with new wp-interactivity directive implementation.

[cbravobernal]

What?

#58743 added support for setting the namespace with just a string in data-wp-interactive. In this PR, I updated the docs accordingly.

[github-actions]

The following accounts have interacted with this PR and/or linked issues. I will continue to update these lists as activity occurs. You can also manually ask me to refresh this list by adding the props-bot label.

If you're merging code through a pull request on GitHub, copy and paste the following into the bottom of the merge commit message.

Co-authored-by: c4rl0sbr4v0 <cbravobernal@git.wordpress.org>
Co-authored-by: SantosGuillamot <santosguillamot@git.wordpress.org>

To understand the WordPress project's expectations around crediting contributors, please review the Contributor Attribution page in the Core Handbook.

[github-actions]

Flaky tests detected in b7f6519.
Some tests passed with failed attempts. The failures may not be related to this commit but are still reported for visibility. See the documentation for more information.

🔍 Workflow run URL: https://github.com/WordPress/gutenberg/actions/runs/7902435264
📝 Reported issues:

• [Flaky Test] default to my only existing menu #59008 in /test/e2e/specs/editor/blocks/navigation.spec.js

[SantosGuillamot]

Looks good to me 🙂

These are a few more places where it could make sense to update it:

• Getting started guide: link.
• Hooks comments: link.
• Store comments: link.

[cbravobernal]

• Getting started guide: link.
• Hooks comments: link.
• Store comments: link.

Will do in follow-up PRs. Thanks Mario!