Add xref to wildcard field type; correct URL for expensive-queries

[smacrakis]

Description

Mentions wildcard field type, which makes these queries more efficient.
Fix URL for expensive-queries

Issues Resolved

NA

Version

2.15 up

Frontend features

Checklist

• [X ] By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license and subject to the Developers Certificate of Origin.
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[github-actions]

Thank you for submitting your PR. The PR states are In progress (or Draft) -> Tech review -> Doc review -> Editorial review -> Merged.

Before you submit your PR for doc review, make sure the content is technically accurate. If you need help finding a tech reviewer, tag a maintainer.

When you're ready for doc review, tag the assignee of this PR. The doc reviewer may push edits to the PR directly or leave comments and editorial suggestions for you to address (let us know in a comment if you have a preference). The doc reviewer will arrange for an editorial review.

[smacrakis]

I am confused by the expression "When you're ready for doc review, tag the assignee of this PR." According to chatgpt, I need to mention ("tag") @kolchfa-aws in a comment, who has already been "assigned" to this issue by github-actions (not to mention the 6 "pending reviewers"). But my pull request already "requested review".

Is the idea that I submit the pull request before I think it is "technically accurate", then sleep on it, and submit it for review later?