(doc) Add release highlight page

This adds a new highlight page for the Chocolatey Agent v2.2.1 bug fix.
We also hide the previous v2.2.0 release from this highlight at the same
time.

Author: AdmiringWorm

src/content/docs/en-us/highlights/2024/12-chocolatey-agent-2.2.0.md

@@ -8,6 +8,6 @@ highlight:
   ctaXref: agent-release-notes
   ctaAnchor: v2.2.0
   ctaText: Read the release notes
-  showOnHome: true
-  showOnHighlights: true
+  showOnHome: false
+  showOnHighlights: false
 ---

src/content/docs/en-us/highlights/2024/12-chocolatey-agent-2.2.1.md

@@ -0,0 +1,12 @@
+---
+order: 0
+xref: highlight-2024-12-09-agent-release-notes
+title: What's new in Chocolatey Agent v2.2.1
+description: Learn all about what's new in Chocolatey Agent v2.2.1
+highlight:
+  postedDateTime: 2024-12-09T00:00:00Z
+  ctaXref: agent-release-notes
+  ctaAnchor: v2.2.1
+  ctaText: Read the release notes
+  showOnHome: true
+  showOnHighlights: true