DOCSP-48773: Server 4.0 EOL (#94)

Author: rustagir

source/whats-new.txt

@@ -12,6 +12,7 @@ What's New
 
 Learn what's new in:
 
+* :ref:`Version 5.5 <kotlin-sync-version-5.5>`
 * :ref:`Version 5.4 <kotlin-sync-version-5.4>`
 * :ref:`Version 5.3 <kotlin-sync-version-5.3>`
 * :ref:`Version 5.2 <kotlin-sync-version-5.2>`
@@ -21,6 +22,17 @@ Learn what's new in:
 * :ref:`Version 5.1 <kotlin-sync-version-5.1>`
 * :ref:`Version 5.0 <kotlin-sync-version-5.0>`
 
+.. _kotlin-sync-version-5.5:
+
+What's New in 5.5
+-----------------
+
+.. important:: Removal of Support for {+mdb-server+} 4.0
+
+   {+driver-short+} v5.5 removes support for {+mdb-server+} 4.0. To
+   learn more about compatible versions of the server, see
+   :ref:`kotlin-sync-compatibility`.
+
 .. _kotlin-sync-version-5.4:
 
 What's New in 5.4