(doc) Add release notes for Agent 2.2.0

This updates the release notes section for Chocolatey Agent to include
the changes that has gone into the v2.2.0 version.

Author: AdmiringWorm

src/content/docs/en-us/agent/release-notes.mdx

@@ -35,6 +35,16 @@ This covers the release notes for the Chocolatey Agent Service (`chocolatey-agen
 
 <ChocolateyComponentDependenciesLink />
 
+## 2.2.0 (December 4, 2024) \{#v2.2.0}
+
+### Feature
+
+- Implement Background Job Management System.
+
+### Improvement
+
+- Add scheduled retry logic when installing Chocolatey Central Management Certificates.
+
 ## 2.1.3 (June 5, 2024) \{#v2.1.3}
 
 Read our [blog post](https://blog.chocolatey.org/2024/06/announcing-cli-230-cle-620-agent213-releases/) about this release.