Regenerate client from commit a663b53 of spec repo (#615)

Co-authored-by: ci.datadog-api-spec <[email protected]>

Author: api-clients-generation-pipeline[bot]

.apigentools-info

@@ -4,13 +4,13 @@
     "spec_versions": {
         "v1": {
             "apigentools_version": "1.4.0",
-            "regenerated": "2020-12-16 15:39:55.185565",
-            "spec_repo_commit": "36e65d3"
+            "regenerated": "2020-12-16 20:45:50.298040",
+            "spec_repo_commit": "a663b53"
         },
         "v2": {
             "apigentools_version": "1.4.0",
-            "regenerated": "2020-12-16 15:40:00.539037",
-            "spec_repo_commit": "36e65d3"
+            "regenerated": "2020-12-16 20:45:56.596909",
+            "spec_repo_commit": "a663b53"
         }
     }
 }

api/v1/datadog/api/openapi.yaml

@@ -778,7 +778,9 @@ paths:
       x-undo:
         type: safe
     post:
-      description: Create a dashboard using the specified options.
+      description: |-
+        Create a dashboard using the specified options. When defining queries in your widgets, take note of which queries should have the `as_count()` or `as_rate()` modifiers appended.
+        Refer to the following [documentation](https://docs.datadoghq.com/developers/metrics/type_modifiers/?tab=count#in-application-modifiers) for more information on these modifiers.
       operationId: CreateDashboard
       requestBody:
         content: