(doc) Update README.md

README.md

@@ -3,10 +3,16 @@ Extension:AskAI
 This extension adds [[Special:AI]],
 which allows user to make AI queries about content of articles in this wiki.
 
+It also adds "Add to AI chat" link to search results on [[Special:Search]].
+
 ## Example configuration
 
 ```php
+// To use ChatGPT API, add the API key to LocalSettings.php:
 $wgAskAIServiceOptionsOpenAI['apiKey'] = 'some-api-key-to-ChatGPT';
+
+// Can choose a model. Default is "gpt-3.5-turbo".
+$wgAskAIServiceOptionsOpenAI['model'] = 'chatgpt-4o-latest';
 ```
 
 ## Debug configuration
@@ -16,3 +22,12 @@ $wgAskAIServiceOptionsOpenAI['apiKey'] = 'some-api-key-to-ChatGPT';
 // instead it will respond with "what did we ask from AI" information.
 $wgAskAIServiceClass = 'MediaWiki\\AskAI\\Service\\DebugService';
 ```
+
+## Specifying instructions for AI
+
+Page [[MediaWiki:Askai-default-instructions]] contains instructions for the AI,
+which can be modified.
+
+AI will receive the text of these instructions,
+then the text of all relevant paragraphs in articles that were selected by user,
+and only then the user's question.