add product diags to 'working with support' (#1921)

👋 howdy, team + @kilfoyle ! Low-level pass at
#1725 🙏

---------

Co-authored-by: Brandon Morelli <[email protected]>
Co-authored-by: David Kilfoyle <[email protected]>
Co-authored-by: shainaraskas <[email protected]>

Author: 4 people

troubleshoot/index.md

@@ -57,14 +57,48 @@ If you have an [Elastic subscription](https://www.elastic.co/pricing), you can c
   If you contact us by email, use the email address you registered with so we can help you more quickly. If your registered email is a distribution list, you can register a second email address with us. Just open a case to let us know the name and email address you want to add.
   :::
 
+  :::{warning}
+  All cases opened by email default to a normal severity level. For incidents, open a case through the [Elastic Support Portal](https://support.elastic.co/) and select the [appropriate severity](https://www.elastic.co/support/welcome#what-to-say-in-a-case).
+  :::
+
 ## Working with support [troubleshoot-work-with-support]
 
-Try these tips when opening a support case:
+When you open a support case:
+
+* Describe the problem with context about the situation and its business severity, as described in [What should I say in my case?](https://www.elastic.co/support/welcome#what-to-say-in-a-case).
+
+  * If an error message was encountered, include the full error message and the timezone-designated timestamp of when the problem occurred.
+
+  * If the problem is UI-related and can't be replicated using API calls, pull a [browser network log](https://www.elastic.co/blog/generating-browser-har-file-kibana-troubleshooting). 
+
+* Upload the related product's diagnostics and debug logs:
+
+  * If hosting on {{serverless-full}} or {{ech}}, Support can pull diagnostics on your behalf as long as you include resource IDs:
+    
+    * {{serverless-full}} Project ID or {{kib}} URL
+    * {{ech}} Deployment ID or {{kib}} URL
 
-* Include the deployment ID that you want help with, especially if you have several deployments.
+  * If hosting on {{ece}} or {{eck}}:
 
-  You can find the deployment ID on the overview page for your cluster in the {{ecloud}} Console.
+    * {{ece}} [diagnostic](/troubleshoot/deployments/cloud-enterprise/run-ece-diagnostics-tool.md) flagging `--deployments` as applicable
+    * {{eck}} [diagnostic](/troubleshoot/deployments/cloud-on-k8s/run-eck-diagnostics.md)
 
-* Describe the problem. Include any relevant details, including error messages you encountered, dates and times when the problem occurred, or anything else you think might be helpful.
+  * If self-hosting:
+
+    * {{es}} [diagnostic](/troubleshoot/elasticsearch/diagnostic.md) and [debug logs](/deploy-manage/monitor/logging-configuration/update-elasticsearch-logging-levels.md)
+    * {{kib}} and {{fleet}} [diagnostic](/troubleshoot/kibana/capturing-diagnostics.md) and [debug logs](/deploy-manage/monitor/logging-configuration/kibana-log-levels.md)
+    
+    * Ingest tools:
+
+      * {{ls}} [diagnostic](/troubleshoot/ingest/logstash/diagnostic.md) and [debug logs](logstash://reference/logging.md)
+      * {{agent}} [diagnostic](https://www.elastic.co/docs/troubleshoot/ingest/fleet/common-problems#trb-collect-agent-diagnostics) and [debug logs](https://www.elastic.co/docs/reference/fleet/monitor-elastic-agent#change-logging-level)
+  
+
+  :::{tip}
+  The {{es}} cluster maintains an advanced task management system, while other products use a simpler polling mechanism. Because of this, some issues appear only in their start-up debug logs. Later logs may note only that the subprocess has stopped or that it has not changed state from an earlier error.
+  :::
+
+  :::{warning}
+  Diagnostics and logs mainly emit product metadata and settings, but they may expose sensitive data which needs to be redacted before being shared outside of your organization. Refer to each product's diagnostics page for information on sanitizing output.
+  :::
 
-* Upload any pertinent files.