Accessibility issue: Heading levels should only increase by one on /django-pattern-library/demo/

[!NOTE]
This is a best-practice recommendation, not a definite WCAG failure.

What

An accessibility scan flagged an element on https://torchbox.github.io/django-pattern-library/demo/ because heading levels should only increase by one. Learn more about why this was flagged by visiting https://dequeuniversity.com/rules/axe/4.11/heading-order?application=playwright.

The following element needs attention:

• <h3 class="heading"> (selector: h3)

To fix this, ensure the order of headings is semantically correct.

Specifically:

Fix any of the following:

• Heading order invalid

Acceptance Criteria

• The specific violation reported in this issue is no longer reproducible.
• The fix MUST meet the accessibility standards specified by the repository or organization (WCAG 2.2 if applicable).
• A test SHOULD be added to ensure this specific violation does not regress.
• This PR MUST NOT introduce any new accessibility issues or regressions.

Open the /django-pattern-library/demo/ URL and inspect the heading hierarchy around the reported h3.heading element. Correct the semantic heading order so the reported axe heading-order violation is gone, then verify the accessibility scan and add a regression test if the repository provides a suitable test location.