use models dot github as the base endpoint

Author: sgoedecke

action.yml

@@ -4,7 +4,7 @@ author: 'GitHub'
 
 # Add your action's branding here. This will appear on the GitHub Marketplace.
 branding:
-  icon: 'play-circle'
+  icon: 'message-square'
   color: red
 
 # Define your inputs here.
@@ -16,11 +16,11 @@ inputs:
   model:
     description: The model to use
     required: false
-    default: 'gpt-4o'
+    default: 'openai/gpt-4o'
   endpoint:
     description: The endpoint to use
     required: false
-    default: 'https://models.inference.ai.azure.com'
+    default: 'https://models.github.ai/inference'
   system-prompt:
     description: The system prompt for the model
     required: false