Update Datadog doc link (#4213)

Author: julianocosta89

data/ecosystem/vendors.yaml

@@ -75,7 +75,7 @@
   commercial: true
 - name: Datadog
   nativeOTLP: true
-  url: 'https://docs.datadoghq.com/tracing/setup_overview/open_standards'
+  url: 'https://docs.datadoghq.com/opentelemetry/'
   contact: ''
   oss: false
   commercial: true

static/refcache.json

@@ -979,6 +979,10 @@
     "StatusCode": 206,
     "LastSeen": "2024-01-30T16:05:06.380053-05:00"
   },
+  "https://docs.datadoghq.com/opentelemetry/": {
+    "StatusCode": 206,
+    "LastSeen": "2024-03-27T15:32:21.711727373Z"
+  },
   "https://docs.datadoghq.com/tracing/connect_logs_and_traces/java/": {
     "StatusCode": 206,
     "LastSeen": "2024-01-18T08:53:29.530053-05:00"