DOC-3526: Add TinyMCE AI improvement release note for Chat sidebar tooltips (TINY-14507)

Author: kemister85

modules/ROOT/pages/8.7.0-release-notes.adoc

@@ -28,6 +28,19 @@ include::partial$misc/admon-releasenotes-for-stable.adoc[]
 
 The following premium plugin updates were released alongside {productname} {release-version}.
 
+=== TinyMCE AI
+
+The {productname} {release-version} release includes an accompanying release of the **TinyMCE AI** premium plugin.
+
+**TinyMCE AI** includes the following improvement.
+
+==== Tooltips are now shown for the Chat sidebar buttons
+// #TINY-14507
+
+The buttons in the Chat sidebar now display tooltips, making their actions easier to identify.
+
+For information on the **TinyMCE AI** plugin, see: xref:tinymceai.adoc[TinyMCE AI].
+
 // === <Premium plugin name 1> <Premium plugin name 1 version>
 
 // The {productname} {release-version} release includes an accompanying release of the **<Premium plugin name 1>** premium plugin.