Add Dropdown Menu for Selecting Specific LLM Model

[MrAnayDongre]

Adding a dropdown menu to the platform will allow users to easily select the LLM they want to use along with a brief description of its features. This will improve the user experience.

[jinhongyii]

Thanks for your suggestion. We will definitely support this feature after we enable more models.

[tqchen]

This is supported in the latest update