Update integrations_autodiscovery.md (#985)

* Update integrations_autodiscovery.md

Noticed a mismatched https://a.cl.ly/qGuYnRqn

* Update integrations_autodiscovery.md

Updated the configuration to match the graph title "Use the spec.override.nodeAgent.extraConfd.configDataMap" -> "Use the spec.override.clusterAgent.extraConfd.configDataMap"
apiVersion: datadoghq.com/v2alpha1
kind: DatadogAgent
metadata:
  name: datadog
spec:
 global:
   credentials:
     apiKey: "<DATADOG_API_KEY>"
     appKey: "<DATADOG_APP_KEY>"
 override:
  nodeAgent:
    extraConfd:
      configDataMap:
        http_check.yaml: |-
          init_config:
          instances:
            - url: "http://%%host%%"
              name: "My service"

docs/integrations_autodiscovery.md

@@ -17,7 +17,7 @@ spec:
      apiKey: "<DATADOG_API_KEY>"
      appKey: "<DATADOG_APP_KEY>"
  override:
-  clusterAgent:
+  nodeAgent:
     extraConfd:
       configDataMap:
         http_check.yaml: |-