website Fix staggered animation page

Pulls out the second, complex staggered animation example from the note into its own section. This was done in lieu of creating a video or animation. This includes 3 new screenshots based on the Flutter app in the example. Fixes #5792
Fixes an omission in the figure caption code to work with different sizes.
Reorganizes the page to provide more context before starting the procedure / example.

Jun 26 '24 23:06 atsansone

Visit the preview URL for this PR (updated for commit 04e5da10e86d19973457d9cd34679eefc457832c):

https://flutter-docs-prod--pr10809-fix-5792-lyn82fv7.web.app

Jun 26 '24 23:06 flutter-website-bot

PLEASE, add a sentence in addition to a bug link. It's a much more efficient use of the reviewer's time.

Jun 26 '24 23:06 sfshaza2

PLEASE, add a sentence in addition to a bug link. It's a much more efficient use of the reviewer's time.

Agreed and fixed.

Jun 27 '24 05:06 atsansone

Please update/rebuild your staged site.

Jul 15 '24 14:07 sfshaza2

/gcbrun

Jul 15 '24 14:07 sfshaza2

@atsansone, please resolve conflicts

Jul 16 '24 23:07 sfshaza2

I'm going to close this for now. This change will likely be picked up again at a later date, with attribution back to this PR.

Jul 30 '24 21:07 redbrogdon