[Docs] How are multiple images handled?

### 📚 The doc issue

InternalVL 1.5 handles multiple images, even if not trained for it, as authors say. But I can't see how lmdeploy handles that or not.

In other cases, models like cogvlm2 may not work with multiple images, how is that handled?

etc.

### Suggest a potential alternative/fix

_No response_