Modify api spec description of create postmortem attachment (#3440)

Co-authored-by: ci.datadog-api-spec <packages@datadoghq.com>

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

.generator/schemas/v2/openapi.yaml

@@ -77857,7 +77857,16 @@ paths:
         If you have any feedback, contact [Datadog support](https://docs.datadoghq.com/help/).'
   /api/v2/incidents/{incident_id}/attachments/postmortems:
     post:
-      description: Create a postmortem attachment for an incident.
+      description: 'Create a postmortem attachment for an incident.
+
+
+        The endpoint accepts markdown for notebooks created in Confluence or Google
+        Docs.
+
+        Postmortems created from notebooks need to be formatted using frontend notebook
+        cells,
+
+        in addition to markdown format.'
       operationId: CreateIncidentPostmortemAttachment
       parameters:
       - description: The ID of the incident

src/main/java/com/datadog/api/client/v2/api/IncidentsApi.java

@@ -1477,6 +1477,10 @@ public CompletableFuture<Attachment> createIncidentPostmortemAttachmentAsync(
   /**
    * Create a postmortem attachment for an incident.
    *
+   * <p>The endpoint accepts markdown for notebooks created in Confluence or Google Docs.
+   * Postmortems created from notebooks need to be formatted using frontend notebook cells, in
+   * addition to markdown format.
+   *
    * @param incidentId The ID of the incident (required)
    * @param body (required)
    * @return ApiResponse&lt;Attachment&gt;