Add more information about where to find the Redirected values

[d-ronnqvist]

Bug/issue #, if applicable:

Summary

This updated the @Redirected documentation to describe how and where the developer can find the redirect values for each page.

Dependencies

None

Testing

• Run swift run docc preview Sources/docc/DocCDocumentation.docc
• Navigate to http://localhost:8080/documentation/docc/redirected

Checklist

Make sure you check off the following items. If they cannot be completed, provide a reason.

• [ ] Added tests
• Ran the ./bin/test script and it succeeded
• Updated documentation if necessary

[patshaughnessy]

This is great; thank you! I left a couple of suggestions with a bit of word-crafting if you're interested.

[d-ronnqvist]

@swift-ci please test