Add link to last year's dance party tutorial on /dance

[molly-moen]

Description

PLC-643: add a link to last year's dance party tutorial on the /dance page, right aligned.
New text:

Visible on desktop and mobile:

Background

This change was added and reverted back in November. It was reverted because there was an issue rendering markdown in staging--that has been investigated and found to be isolated to staging, and the issue has been fixed. There was also discussion at the time about the amount of whitespace below the text, so I updated the padding to have the same amount of whitespace between the new text and the "In partnership" section as there previously was between the boxes and the "In partnership" section.
For reference, here are the desktop and mobile views without the text:

Testing story

This is a content change, tested locally. This will also cause a diff in tutorial_landing_pages.feature.

Reviewer Checklist:

• Tests provide adequate coverage
• Code is well-commented
• New features are translatable or updates will not break translations
• Relevant documentation has been added or updated
• User impact is well-understood and desirable
• Pull Request is labeled appropriately
• Follow-up work items (including potential tech debt) are tracked and linked

[islemaster]

Looks great! Thank you for picking this up!