Migrate 40th anniversary timeline to CMS

[patphongs]

Summary

What we're after:
Migrate the existing 40th anniversary timeline from the legacy page into our CMS. We'll rename it to "FEC timeline", as this will be the base in which we insert content as time goes by.

Related issues

List any relevant related issue(s)

• Innovation (Anniversary Page work) - Experiment with Wagtail templates to see if any fit a "timeline"  #5773

Action items

• Transfer all timeline content into a new CMS timeline page 🔒
• Move all images from the transition S3 bucket and upload them to the CMS media library. (John added these to a new images/timeliine folder in S3 bucket)
• Ensure styling is consistent with our current design system (headings, spacing, colors, etc.).
• Confirm videos are embedded properly or link to them if hosting on YouTube.
• Ensure the timeline is responsive and accessible (mobile-friendly and screen-reader compatible).
• Add redirects from old transition URL.
• Archive the old legacy page

Completion criteria

• FEC timeline page is published
• All images are uploaded to CMS
• Remove timeline Images from transition, delete temporary dedicated S3 directory #6814

Future work

Review and revise timeline content to align with the FEC content style guide.