[DOC-12715] Document New Search Request Params for Search Fine-Tuning (#291)

* [quickfix]: quickfix: strange font problem on diagram (#274)

Seems to have been caused by extra space in the label.

* [DOC-12610]: Document `nprobe` tweaking

* [DOC=12610]: Moved fine-tuning menu entry.
[DOC=12610]: Moved the stem declaration; wasn't working in the old position.

* [DOC=12610]:
Moved and reworded the sections for clarity.
Adding link to search-index-params.adoc

* [DOC-12715] Add documentation to the JSON search request example and topics around the new added memory-efficient setting and the params object for probe and centroid tuning

* [DOC-12715] Adding on to Ray's documentation to provide a link to Search Request Params.

* [DOC-12715] Comments from peer review

---------

Co-authored-by: Ray Offiah <[email protected]>
Co-authored-by: Ray Offiah <[email protected]>

Author: sarahlwelton

modules/search/pages/search-request-params.adoc

@@ -281,6 +281,40 @@ If you reduce your `ivf_max_codes_pct` value, the Search Service accesses fewer
 In the example, the Search Service searches only `0.2%` of the available centroids in your vector data. 
 |====
 
+[#knn-params]
+=== Knn params Object 
+
+Use the `params` object inside a `knn` object to fine tune the probes and centroids the Search Services uses and searches while running a Vector Search request. 
+
+The `params` object can contain the following properties: 
+
+[cols="1,1,1,4"]
+|====
+|Property |Type |Required? |Description
+
+|ivf_nprobe_pct |Number (percentage) |No a|
+
+Set the `ivf_nprobe_pct` value to control the percentage of probes, or the percentage of clusters, that the Search Service searches during a single Vector Search query.
+
+The Search Service automatically calculates a default `nprobe` percentage based on the vectors in a given partition of your Vector Search index.
+For more information about this calculation, see xref:vector-search:fine-tune-vector-search.adoc[].
+
+If you set the value of `ivf_nprobe_pct` higher than this default calculated value, the Search Service will search a higher percentage of clusters in your processed vectors.
+This can increase your accuracy and recall for Vector Search, but requires more compute time for each query. 
+
+In the example, the Search Service searches only `1%` of the total available clusters. 
+
+|ivf_max_codes_pct |Number (percentage out of 100) |No a|
+
+Set the `ivf_max_codes_pct` value to control the maximum number of centroids that the Search Service accesses during a single Vector Search query. 
+
+By default, this value is always 100%. 
+
+If you reduce your `ivf_max_codes_pct` value, the Search Service accesses fewer centroids, which reduces your Vector Search accuracy and recall, but gives faster compute times for your search. 
+
+In the example, the Search Service searches only `0.2%` of the available centroids in your vector data. 
+|====
+
 [#query-object]
 == Query Object