Add 'metrics' tag to /api/v4/client_perf endpoint (#29612)

* Add 'metrics' tag to client_perf endpoint

* Add metrics tag to introduction.yaml

api/v4/source/introduction.yaml

@@ -559,6 +559,8 @@ tags:
     description: Endpoints related to import files.
   - name: exports
     description: Endpoints related to export files.
+  - name: metrics
+    description: Endpoints related to metrics, including the Client Performance Monitoring feature.
 x-tagGroups:
   - name: Overview
     tags:
@@ -615,6 +617,7 @@ x-tagGroups:
       - usage
       - reports
       - custom profile attributes
+      - metrics
 servers:
   - url: http://your-mattermost-url.com
   - url: https://your-mattermost-url.com

api/v4/source/metrics.yaml

@@ -1,5 +1,7 @@
   /api/v4/client_perf:
     post:
+      tags:
+        - metrics
       summary: Report client performance metrics
       description: >
         Uploads client performance measurements to the server as part of the Client Performance Monitoring feature.