Review and update pages marked as Architecture: Needs Review

[jonthysell]

Page url

https://microsoft.github.io/react-native-windows/

Problem Description

Starting with PR #1029, pages are now tagged with Architecture:

This issue is tracking that we need to actually review all of the pages marked and evaluate which badge is more correct. For each page, we'll want to:

1. Review the page's contents
2. If necessary, make any updates to the docs (if the content has a meaningful difference for old and new architectures, make it clear)
3. Remove the "Architecture Review Needed" note at the top of the page
4. Replace the tag with the correct one

[chrisglein]

Example page with new tags: https://microsoft.github.io/react-native-windows/docs/next/getting-started

Search for pages that have this tag: https://github.com/search?q=repo%3Amicrosoft%2Freact-native-windows-samples%20https%3A%2F%2Fimg.shields.io%2Fbadge%2Farchitecture-needs_review-red&type=code
(currently 28)