docs: on google-genai vs google-vertexai (#20713)

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- [ ] **PR title**: "docs: added a description of differences
langchain_google_genai vs langchain_google_vertexai"


- [ ]
- **Description:** added a description of differences
langchain_google_genai vs langchain_google_vertexai

docs/docs/integrations/platforms/google.mdx

@@ -4,6 +4,9 @@ All functionality related to [Google Cloud Platform](https://cloud.google.com/)
 
 ## LLMs
 
+We recommend individual developers to start with Gemini API (`langchain-google-genai`) and move to Vertex AI (`langchain-google-vertexai`) when they need access to commercial support and higher rate limits. If you’re already Cloud-friendly or Cloud-native, then you can get started in Vertex AI straight away.
+Please, find more information [here](https://ai.google.dev/gemini-api/docs/migrate-to-cloud).
+
 ### Google Generative AI
 
 Access GoogleAI `Gemini` models such as `gemini-pro` and `gemini-pro-vision` through the `GoogleGenerativeAI` class.