Update custom serialization docs (#4580) (#4587)

This commit updates the custom serialization docs that discuss using
JsonNetSerializer.

1. Remove the implication that the internal serializer
is based on Json.NET.
2. Include recommendation to hook up JsonNetSerializer when using
Newtonsoft.Json.Linq types like JObject

Co-authored-by: Russ Cam <[email protected]>

Author: github-actions[bot]

docs/client-concepts/high-level/serialization/custom-serialization.asciidoc

@@ -115,8 +115,11 @@ back to NEST's built-in serializer.
 
 We ship a separate {nuget}/NEST.JsonNetSerializer[NEST.JsonNetSerializer] package that helps in composing a custom `SourceSerializer`
 using `Json.NET`, that is smart enough to delegate the serialization of known NEST types back to the built-in
-`RequestResponseSerializer`. This package is also useful if you want to control how your documents and values are stored
-and retrieved from Elasticsearch using `Json.NET`, without interfering with the way NEST uses `Json.NET` internally.
+`RequestResponseSerializer`. This package is also useful if
+
+. You want to control how your documents and values are stored and retrieved from Elasticsearch using `Json.NET`
+
+. You want to use `Newtonsoft.Json.Linq` types such as `JObject` within your documents
 
 The easiest way to hook this custom source serializer up is as follows
 

tests/Tests/ClientConcepts/HighLevel/Serialization/CustomSerialization.doc.cs

@@ -120,8 +120,10 @@ public class MyPercolationDocument
 		 *
 		 * We ship a separate {nuget}/NEST.JsonNetSerializer[NEST.JsonNetSerializer] package that helps in composing a custom `SourceSerializer`
 		 * using `Json.NET`, that is smart enough to delegate the serialization of known NEST types back to the built-in
-		 * `RequestResponseSerializer`. This package is also useful if you want to control how your documents and values are stored
-		 * and retrieved from Elasticsearch using `Json.NET`, without interfering with the way NEST uses `Json.NET` internally.
+		 * `RequestResponseSerializer`. This package is also useful if
+		 *
+		 * . You want to control how your documents and values are stored and retrieved from Elasticsearch using `Json.NET`
+		 * . You want to use `Newtonsoft.Json.Linq` types such as `JObject` within your documents
 		 *
 		 * The easiest way to hook this custom source serializer up is as follows
 		 */