Add Vercel metrics metadata (DataDog#2215)

* Add Vercel metrics metadata

* Fix execution metric unit to use microseconds

* Add vercel.requests as a check metric

vercel/manifest.json

@@ -38,7 +38,7 @@
       },
       "metrics": {
         "prefix": "vercel.",
-        "check": [],
+        "check": "vercel.requests",
         "metadata_path": "metadata.csv"
       },
       "service_checks": {
@@ -51,4 +51,4 @@
       "Vercel": "assets/dashboards/vercel_overview.json"
     }
   }
-}
+}

vercel/metadata.csv

@@ -1 +1,9 @@
 metric_name,metric_type,interval,unit_name,per_unit_name,description,orientation,integration,short_name,curated_metric
+vercel.requests,count,,request,,The number of requests to each route in a Vercel project,0,vercel,requests,
+vercel.builds.build_count,count,,build,,The number of builds of a Vercel project,0,vercel,builds,
+vercel.functions.memorysize,gauge,,mebibyte,,The memory allocated to a Vercel Serverless Function,0,vercel,allocated memory,
+vercel.functions.max_memory_used,gauge,,mebibyte,,The max memory used by a Vercel Serverless Function invocation,0,vercel,max memory used,
+vercel.functions.invocations,count,,invocation,,The number of invocations of a Vercel Serverless Function,0,vercel,invocations,
+vercel.functions.execution,gauge,,microsecond,,The execution time of a Vercel Serverless Function invocation,0,vercel,execution time,
+vercel.functions.errors,count,,error,,The number of errors in a Vercel Serverless Function,-1,vercel,errors,
+vercel.functions.duration,gauge,,nanosecond,,The duration of a Vercel Serverless Function invocation,0,vercel,invocation duration,