docs: Fix alternatives table overflow on mobile

[robintindale]

Summary

• Wrap the Alternatives comparison table in the reusable .responsive-table container.
• Enable horizontal scrolling below the Docusaurus mobile breakpoint so all columns remain readable on narrow screens.
• Limit the change to this table; desktop layout and other documentation tables are unchanged.

Testing

• npm run lint -- --max-warnings=0
• npm run build
• Verified change works on mobile view

[robintindale]

Visual comparison

before:

after:

[Classic298]

thanks makes sense. if you find others let me know