Updates for tfc-agent release 1.15.2 (#102)

Author: natalie-todd

website/docs/cloud-docs/agents/changelog.mdx

@@ -18,6 +18,17 @@ within each release are categorized into one or more of the following labels:
 Each version below corresponds to a release artifact available for download on
 the official [releases website](https://releases.hashicorp.com/tfc-agent/).
 
+## 1.15.2 (05/29/2024)
+
+BUG FIXES:
+
+* Fixed consistency of the `status.<idle,busy>` gauge metrics (#680)
+* Fixed cpu utilization gauge and clarified metric names (#681)
+
+IMPROVEMENTS:
+
+* Improved collection of errors from VCS Repositories when performing ingress (#683)
+
 ## 1.15.1 (05/01/2024)
 
 IMPROVEMENTS: