Adds RAG for alerts info to the AI Assistant page

docs/assistant/security-assistant.asciidoc

@@ -166,20 +166,32 @@ When you include a particular event as context, you can use a similar interface
 +
 The *Show anonymized* toggle controls whether you see the obfuscated or plaintext versions of the fields you sent to AI Assistant. It doesn't control what gets obfuscated — that's determined by the anonymization settings. It also doesn't affect how event fields appear _before_ being sent to AI Assistant. Instead, it controls how fields that were already sent and obfuscated appear to you.
 
-* **Knowledge base:** Use retrieval-augmented generation to provide specialized knowledge of the Elastic Search Query Language ({esql}) to AI Assistant. For example, with the knowledge base active, you can ask AI Assistant to help you write an {esql} query for a particular use case, or ask it to answer general questions about {esql} syntax and usage. Without the knowledge base enabled, AI Assistant will not be able to answer questions about {esql}.
+[[ai-assistant-knowledge-base]]
+* **Knowledge base:** Use retrieval-augmented generation to provide additional context to AI Assistant. 
 +
 beta::[]
-+
-To enable the knowledge base:
-+
+
+Enable AI Assistant to answer questions about the Elastic Search Query Language ({esql}):
+
 . Enable the Elastic Learned Sparse EncodeR (ELSER). This model provides additional context to the third-party LLM. To learn more, refer to {ml-docs}/ml-nlp-elser.html#download-deploy-elser[Configure ELSER].
 . Initialize the knowledge base by clicking *Initialize*.
 . Turn on the *Knowledge Base* option.
 . Click *Save*. The knowledge base is now active.
 +
-When the knowledge base is active, a quick prompt for {esql} queries becomes available. It provides a good starting point for your {esql} conversations and questions.
+When this setting is enabled, AI Assistant can answer questions about {esql}. For example, it can help you write an {esql} query for a particular use case, or answer general questions about {esql} syntax and usage. 
+A quick prompt for {esql} queries becomes available, which provides a good starting point for your {esql} conversations and questions. When this setting is disabled, AI Assistant can not answer questions about {esql}.
+
+Enable AI Assistant to answer questions about alerts in your environment:
 
+. Turn on the **Alerts** setting.
+. Use the slider to select how many alerts to send to AI Assistant. 
++
+When this setting is enabled, AI Assistant will receive multiple alerts as context for each of your prompts. It will receive alerts from the last 24 hours that have a status of `open` or `acknowledged`, ordered first by risk score, then by recency, and excluding building block alerts. 
+
+[role="screenshot"]
+image::images/knowledge-base-settings.png[AI Assistant's settings menu, open to the Knowledge Base tab]
 [discrete]
+
 [[ai-assistant-queries]]
 ### Get the most from your queries