Generate classes for responsive screen-reader-only hiding.

[nenaroig]

Description

Added responsive visually hidden utility classes (e.g., .visually-lg-hidden) that apply the visually-hidden styles starting at each breakpoint and above. This allows easier control over screen-reader-only content visibility based on viewport size.

Motivation & Context

Bootstrap currently has .visually-hidden and .visually-hidden-focusable utilities, but no responsive variants. These new classes simplify accessibility-focused UI work by enabling developers to conditionally hide content at specific breakpoints without writing custom CSS.

Type of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Refactoring (non-breaking change)
• Breaking change (fix or feature that would change existing functionality)

Checklist

• [ x] I have read the contributing guidelines
• [ x] My code follows the code style of the project (using npm run lint)
• My change introduces changes to the documentation
• I have updated the documentation accordingly
• I have added tests to cover my changes
• [ x] All new and existing tests passed

Live previews

• https://deploy-preview-41519--twbs-bootstrap.netlify.app/

Related issues

• Closes Visually-hidden breakpoints #40859