Fix table width issue on important upgrade notes page (#8080)

Fixed horizontal scrolling problem by implementing page-specific responsive table styling that only affects the upgrade notes table while preserving existing behavior for all other documentation tables.

Key improvements:
- Responsive table layout with 25%/75% column proportions
- Page-specific CSS targeting using section#important-upgrade-notes
- Proper word wrapping and vertical alignment for long content
- Unified styling for both table headers (th) and data cells (td)
- Eliminates horizontal scrollbar while maintaining readability

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Carrie Warner (Mattermost) <74422101+cwarnermm@users.noreply.github.com>

Author: 3 people