DOCSP-37847: Add GraalVM to what's new (#536)

* DOCSP-37847: Add GraalVM to what's new

* tech review

* spacing

Author: norareidy

source/whats-new.txt

@@ -46,6 +46,12 @@ What's New in 5.1
    To avoid breaking changes in future major releases of the driver,
    replace any application code that depends on deprecated program elements.
 
+This section includes the following information:
+
+- :ref:`java-deprecations-5.1`
+- :ref:`java-improvements-5.1`
+- :ref:`java-new-features-5.1`
+
 .. _java-deprecations-5.1:
 
 Deprecations in 5.1
@@ -56,13 +62,19 @@ Deprecations in 5.1
   deployment, see :manual:`Release Notes </release-notes>` in the {+mdb-server+}
   manual.
 
+.. _java-improvements-5.1:
+
+Improvements in 5.1
+~~~~~~~~~~~~~~~~~~~
+
+- Internal testing of GraalVM native image technology. These tests involve building
+  native applications by using the GraalVM native-image tool.
+
 .. _java-new-features-5.1:
 
 New Features in 5.1
 ~~~~~~~~~~~~~~~~~~~
 
-The 5.1 driver release includes the following new features:
-
 - Introduces the ``serverMonitoringMode`` connection URI option. For more information about
   this option, see the :ref:`connection-options` guide.