feat!: Make terms bold instead of descriptions in Description List

[VincentSmedinga]

Describe the pull request

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What

Following a request from our community, We’ve revised our earlier decision to display the descriptions of a Description List with bold text. Instead, we want the terms to be bold.

Why

Regular text is easier to read, especially if it is long as in form summaries. Making terms bold matches the header in forms. All communities in NLDS use bold for the terms, not the descriptions.

How

• Updated the relevant tokens and CSS.
• Removed a list-wide font-weight token that wasn’t used. This makes the change breaking.
• Improved the content of the examples, sourcing from our editorial guide.
• Changed ‘details’ to ‘description’ in docs – because MDN does so for <dd> and it does not clash with <details>.

Checklist

Before submitting your pull request, please ensure you have done the following. Check each checkmark if you have done so or if it wasn't necessary:

• Add or update unit tests
• Add or update documentation
• Add or update stories
• Add or update exports in index.* files
• Start the PR title with a Conventional Commit prefix, as explained here.

Additional notes

• We should rename DescriptionList.Details to DescriptionList.Description and the details tokens and classes. Let’s do this in a separate PR.
• An inline style in the ‘Multiple terms’ example hides a bug (a ticket exists for it).
• Customizing the widths of the columns, another request from the same source, also has its own ticket.