[Ready] Update docs in the notebooks section

[stichbury]

NOTE: Kedro datasets are moving from kedro.extras.datasets to a separate kedro-datasets package in
kedro-plugins repository. Any changes to the dataset implementations
should be done by opening a pull request in that repository.

Description

Ongoing work to improve section of docs. Addresses #2845

Development notes

Checklist

• Read the contributing guidelines
• Signed off each commit with a Developer Certificate of Origin (DCO)
• Opened this PR as a 'Draft Pull Request' if it is work-in-progress
• Updated the documentation to reflect the code changes
• Added a description of this change in the RELEASE.md file
• Added tests to cover my changes
• Checked if this change will affect Kedro-Viz, and if so, communicated that with the Viz team

[stichbury]

@astrojuanlu Ready for an initial review. More comments from me over on #2855

[astrojuanlu]

Looking into this when https://beta.readthedocs.org/projects/kedro/builds/22122501/ passes, added nbsphinx to dependencies

In the meantime, what notebook version do you have? I think it would be a good moment to take those screenshots with >=7.0, I can help with this

[stichbury]

Closing this PR and creating two new ones as it's getting too large.