Audit links on Design principles page

[finekatie]

Create document that lists all resource links from the Design principles page.

Document is here: https://docs.google.com/spreadsheets/d/1n2qzP7F2osR-kis2wSJcwZsXZ69WUMzQzxvVsMnc7PA
Make recommendations and review with team.
Use approved recommendations to update page (related issue #2573 ) and share progress on TTS audit

[finekatie]

Findings:

There are 98 links on the page
22 links are broken or redirected and need correction, or are duplicative
38 links may be outdated, and need some kind of review
38 links are ok.

[brunerae]

Updates to be made as part of #2573