Redesign article page for better usability and performance

[arvindpdmn]

• Related issues: Improve Lighthouse score for article page #464 and CLS, FCP and FID performance improvements #436
• Copied from Website Analysis report (v1.3):

1. Reader can get distracted: read the summary or the milestones? Milestones section very prominent and demands attention. This can be unsettling for some readers. Two readers gave this comment.
2. Author information is too prominent. This was done to encourage authors but this has not worked.
3. One reader questioned the way title is highlighted.
4. Another comment is if we really need the section headers: Summary, Milestones, etc.
5. On mobiles, Milestones comes before Discussion. Should we not put Discussion first?
6. Images are small. Need to zoom in to view them. This was inspired by Wikipedia. Why not show them as large as possible?
7. Another design comment: use white background rather than grey.
8. One reader wanted to see the list of questions at a glance.
9. To encourage users to navigate to other pages, give priority to tags and See Also.
10. See Also may need to be redesigned. Plus sign is not intuitive. Consider also how unpublished articles will appear in See Also.

[arvindpdmn]

Wikipedia's redesign: https://www.reviewgeek.com/55164/wikipedia-is-shaking-up-its-iconic-look-for-the-first-time-in-10-years/

[arvindpdmn]

Done