added Ditto 2.2.2 relase notes

Signed-off-by: Thomas Jaeckle <thomas.jaeckle@bosch.io>

documentation/src/main/resources/_data/sidebars/ditto_sidebar.yml

@@ -23,6 +23,9 @@ entries:
       - title: Release Notes
         output: web
         folderitems:
+          - title: 2.2.2
+            url: /release_notes_222.html
+            output: web
           - title: 2.2.1
             url: /release_notes_221.html
             output: web

documentation/src/main/resources/pages/ditto/release_notes_222.md

@@ -0,0 +1,21 @@
+---
+title: Release notes 2.2.2
+tags: [release_notes]
+published: true
+keywords: release notes, announcements, changelog
+summary: "Version 2.2.2 of Eclipse Ditto, released on 05.01.2022"
+permalink: release_notes_222.html
+---
+
+This is a bugfix release, no new features since [2.2.1](release_notes_221.html) were added.
+
+## Changelog
+
+Compared to the latest release [2.2.1](release_notes_221.html), the following bugfixes were added.
+
+### Bugfixes
+
+#### Update logback to 1.2.10 due to "possibility of vulnerability"
+
+The used logback version was updated to version 1.2.10 to mitigate a [known CVE](https://cve.report/CVE-2021-42550)
+with logback versions smaller than 1.2.9.