add list of external LLMs we facilitate access to right now

  	modified:   docs/genai/02_external_llms/02_catalogue.md

Author: s-sajid-ali

docs/genai/02_external_llms/02_catalogue.md

@@ -1,11 +1,11 @@
 # External models listed by provider
 
 ## OpenAI
-GPT-4o-mini
-text-embedding-3-small
+-   gpt-4o-mini
+-   o3-mini
+-   text-embedding-3-small
 
 ## VertexAI
-Gemini-2.0-*
-
-
-
+-   Gemini-2.0 models (flash, flash-lite)
+-   Gemini-1.5 models (flash, pro)
+For a comprehensive list, please [refer to the VertexAI documentation](https://cloud.google.com/vertex-ai/generative-ai/docs/learn/models).