Fix typo in 'media-breakpoint-between' in migration docs

[sgilberg]

Description

A simple docs fix - I noticed the use of 'media-between' where it should be 'media-breakpoint-between' based on the context.

Motivation & Context

Clarifies migration needs for the user

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

• I have read the contributing guidelines
• 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
• All new and existing tests passed

Live previews

N/A

Related issues

N/A

[julien-deramond]

Thanks for the PR @sgilberg
LGTM