Update changelog in preparation for 8.6.1 (#321)

* Update changelog in preparation for 8.6.1

* addition to changelog

Author: kevinlog

package/endpoint/changelog.yml

@@ -3,6 +3,14 @@
     - description: ""
       type: enhancement
       link: ""
+- version: "8.6.1"
+  changes:
+    - description: Rename process.Ext.session to session_info and restore legacy keyword field
+      type: enhancement
+      link: https://github.com/elastic/endpoint-package/pull/318
+    - description: Update ECS to 8.5.2
+      type: enhancement
+      link: https://github.com/elastic/endpoint-package/pull/322
 - version: "8.6.0"
   changes:
     - description: Add entity_id to file and network