Update offcanvas.md To Mention Adding data-bs-target for Close Buttons in Offcanvas Components

[ASchoe311]

Description

Added a note in the Responsive section to indicate that "Close" buttons in responsive offcanvas components must have a data-bs-target attribute to function.

Motivation & Context

It is unclear that data-bs-target is required for the close button in responsive offcanvas components. I was only able to realize this by finding an open issue from 2022.

Type of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [x] 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)
• [x] My change introduces changes to the documentation
• [x] 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-41325--twbs-bootstrap.netlify.app/

Related issues

#36962

[mdo]

I edited and reorganized the content there. Thanks!