docs: updated to reflect fallbacks when ba11y plugin is not active

[troychaplin]

Pull Request

Description

Type of Change

• 🐛 Bug fix
• ✨ New accessibility check
• 🔌 New developer API feature
• 📚 Documentation update
• 🔧 Code refactoring
• ♿ Accessibility improvement
• 💥 Breaking change

Related Issues

Related issue(s): #{add issue}

Changes Made

Testing

Environment:

• WordPress Version:
• Browser(s) tested:

Test Cases: (check what applies to your change)

For new accessibility checks:

• Tested error state (red border/message)
• Tested warning state (yellow border/message)
• Tested valid state (no indicators)
• Publishing prevention works (for errors)

For updated accessibility checks:

• Existing functionality still works
• New behavior works as expected
• No regressions in other blocks

For new developer API features:

• API functions work as documented
• Hooks/filters fire correctly
• External plugin integration tested

For developer API updates:

• Backward compatibility maintained
• Existing integrations still work
• New functionality accessible

General testing:

• No console errors
• Tested in wp-env environment
• Works across different WordPress blocks

Screenshots

Developer API Impact (if applicable)

• No API changes
• New hooks/filters added
• Breaking changes to existing API
• Documentation updated

Checklist

• Code follows WordPress standards
• No PHP/JavaScript errors
• Tested in wp-env environment
• Documentation updated (if needed)