docs migration - Core Libraries

Source: documentation/core-libraries/index.md
Proposed disposition: Needs determination — this page provides overview descriptions of Foundation, libdispatch, XCTest, and Swift Testing, each of which has its own repository and documentation. The _foundation.md, _libdispatch.md, _swift-testing.md, and _xctest.md include files are consumed by this page and should be dealt with together.
Reviewer: Foundation team, libdispatch team, XCTest team, and Swift Testing team — one sign-off per library section

Checklist

• Determine disposition (suggested: Deprecate) and confirm redirect target for each library
• Identify current canonical documentation URLs for Foundation, libdispatch, XCTest, and Swift Testing
• Add redirect_to: to the swift.org source file's front matter (to best single landing page, or update the page to be a plain links page)
• Remove or archive the four include files once the redirect is in place
• Submit redirect PR to swift-org-website

Start with documentation/core-libraries/index.md and its _foundation.md, _libdispatch.md, _swift-testing.md, and _xctest.md includes. Determine the disposition and canonical documentation URL for each library, then review the source front matter and redirect approach. Done means the redirect or links-page decision is recorded, obsolete includes are removed or archived, and the redirect PR is submitted to swift-org-website.