[Kotlin Sync] Support naming strategy for bson-kotlinx (#90)

* snake case example

* move release note

* dependency name

* RR feedback

* update release note

(cherry picked from commit 84aa7bb)

Author: rachel-mack

source/data-formats/serialization.txt

@@ -227,6 +227,24 @@ encode defaults:
    :end-before: end-codec
    :dedent:
 
+.. _kotlin-sync-serialization-snake-case-eg:
+
+Implement Snake Case Naming Strategy
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+When using ``bson-kotlinx`` package v5.4 or later, you can direct the driver to
+serialize data class fields names written in camel case to snake case in MongoDB.
+The following example shows how to create and register a custom codec
+to convert data class field names into snake case by setting the
+``bsonNamingStrategy`` parameter in a codec:
+
+
+.. literalinclude:: /includes/data-formats/serialization.kt
+   :language: kotlin
+   :start-after: start-snake-case
+   :end-before: end-snake-case
+   :dedent:
+
 To learn more about the methods and classes mentioned in this section,
 see the following API documentation:
 
@@ -238,6 +256,8 @@ see the following API documentation:
 
 - `BsonConfiguration
   <{+api-root+}/bson-kotlinx/bson-kotlinx/org.bson.codecs.kotlinx/-bson-configuration/index.html>`__
+
+- `BsonNamingStrategy <{+api-root+}/bson-kotlinx/bson-kotlinx/org.bson.codecs.kotlinx/-bson-naming-strategy/index.html>`__
 
 .. _kotlin-sync-polymorphic:
 

source/includes/data-formats/serialization.kt

@@ -101,6 +101,16 @@ fun main() {
     )
     // end-codec
 
+    // start-snake-case
+    val myCustomCodec = KotlinSerializerCodec.create<PaintOrder>(
+        bsonConfiguration = BsonConfiguration(bsonNamingStrategy = BsonNamingStrategy.SNAKE_CASE)
+    )
+
+    val registry = CodecRegistries.fromRegistries(
+        CodecRegistries.fromCodecs(myCustomCodec), collection.codecRegistry
+    )
+    // end-snake-case
+
     // start-poly-operations
     val collection = database.getCollection<Person>("school")
 

source/whats-new.txt

@@ -29,6 +29,10 @@ What's New in 5.4
 The 5.4 driver release includes the following changes, fixes,
 and features:
 
+- Adds ``BsonConfiguration`` support for bson-kotlinx snake case conversion
+  during serialization. To learn more, see the
+  :ref:`kotlin-sync-serialization-snake-case-eg` on the Serialization page.
+
 .. sharedinclude:: dbx/jvm/v5.4-wn-items.rst
 
    .. replacement:: install-bom-link