Moves the search sort docs from the deprecated 'Request Body Search'
page to a new subpage of 'Run a search'.
No substantive changes were made to the content.
* Removes experimental.
* Replaces `"v"` (for value) with `"m"` (for metric).
* Move the note about tiebreaking into the list of limitations of the
sort.
* Explain how you ask for `metrics`.
* Clean up some wording.
* Link to the docs from `top_metrics`.
Closes#51813
This changes the `top_metrics` aggregation to return metrics in their
original type. Since it only supports numerics, that means that dates,
longs, and doubles will come back as stored, with their appropriate
formatter applied.
The `top_metrics` agg is kind of like `top_hits` but it only works on
doc values so it *should* be faster.
At this point it is fairly limited in that it only supports a single,
numeric sort and a single, numeric metric. And it only fetches the "very
topest" document worth of metric. We plan to support returning a
configurable number of top metrics, requesting more than one metric and
more than one sort. And, eventually, non-numeric sorts and metrics. The
trick is doing those things fairly efficiently.
Co-Authored by: Zachary Tong <zach@elastic.co>
James Rodewig
Gil Raphaelli
Paweł Krześniak
Nik Everett