Accessibility: skipped heading levels (h2 -> h5)

[kburk1997]

Describe the bug

1. Go to Redocly Demo
2. Run WAVE Chrome Extension
3. Observe heading levels are skipped, h2 -> h5 (see Screenshots)

Expected behavior
Heading levels should not be skipped.

Screenshots

Additional context
Deque University - Heading levels should only increase by one