Remove Expandable rows from website

[oliviaflory]

After reviewing the content the following pages should be removed from the datagrid/data table pattern:

• Expandable rows

Considerations:

1. Most of the documentation will be saved on the old site/repo in case we need to add anything back.
2. Do we keep the expandable rows example in our Tanstack demos? (Currently missing from WC)

Tasks

• Remove Expandable rows page
• Remove any related images used only on that page
• Update nav.yaml file
• Double check if any pages link directly to Expandable rows and adjust content/remove links
• Open a PR

[RichKummer]

We'll keep the Tanstack examples in this case, but remove the Expandable rows page from the website.