Add another metric to check (DataDog#20861)

Author: sarah-witt

proxmox/manifest.json

@@ -36,7 +36,10 @@
       },
       "metrics": {
         "prefix": "proxmox.",
-        "check": "proxmox.api.up",
+        "check": [
+          "proxmox.api.up",
+          "proxmox.cpu"
+        ],
         "metadata_path": "metadata.csv"
       },
       "process_signatures": [
@@ -64,4 +67,4 @@
     "homepage": "https://www.datadoghq.com",
     "sales_email": "info@datadoghq.com"
   }
-}
+}